To all those who have been having trouble with ‘No Response from Modbus slave 2’,
I’ve got this:
using this flow:
[{"id":"cf294862.7e8b68","type":"tab","label":"SDM","disabled":false,"info":""},{"id":"39fe0e66.c9799a","type":"comment","z":"cf294862.7e8b68","name":"SDM230 Energy Meter","info":"","x":160,"y":80,"wires":[]},{"id":"94d8cc20.dddda8","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 230 Voltage","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"1","dataType":"InputRegister","adr":"0","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":140,"wires":[["8e5f6d2b.cfc398"],[]]},{"id":"8e5f6d2b.cfc398","type":"function","z":"cf294862.7e8b68","name":"Voltage","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"voltage\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":380,"y":140,"wires":[["9f73b54.da6f348","755cac29.d21844"]]},{"id":"9f73b54.da6f348","type":"ui_text","z":"cf294862.7e8b68","group":"52e8e5ce.130db4","order":1,"width":0,"height":0,"name":"","label":"Voltage","format":"{{msg.payload}} V","layout":"row-spread","x":560,"y":140,"wires":[]},{"id":"2d92317c.0c8ff6","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 230 Current","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"1","dataType":"InputRegister","adr":"6","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":200,"wires":[["ffab16d2.30bce8"],[]]},{"id":"ffab16d2.30bce8","type":"function","z":"cf294862.7e8b68","name":"Current","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"current\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":380,"y":200,"wires":[["3dce87d7.a582d","755cac29.d21844"]]},{"id":"3dce87d7.a582d","type":"ui_text","z":"cf294862.7e8b68","group":"52e8e5ce.130db4","order":2,"width":0,"height":0,"name":"","label":"Current","format":"{{msg.payload}} A","layout":"row-spread","x":560,"y":200,"wires":[]},{"id":"dd502269.cf075","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 230 Power","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"1","dataType":"InputRegister","adr":"12","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":260,"wires":[["7c9ac9f6.45e8c"],[]]},{"id":"7c9ac9f6.45e8c","type":"function","z":"cf294862.7e8b68","name":"Power","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"power\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":260,"wires":[["ecdf6f70.f8cf8","755cac29.d21844"]]},{"id":"ecdf6f70.f8cf8","type":"ui_text","z":"cf294862.7e8b68","group":"52e8e5ce.130db4","order":3,"width":0,"height":0,"name":"","label":"Power","format":"{{msg.payload}} W","layout":"row-spread","x":550,"y":260,"wires":[]},{"id":"2a33780f.6c1dc8","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 230 Energy Imp","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"1","dataType":"InputRegister","adr":"72","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":180,"y":320,"wires":[["39e8800a.b2141"],[]]},{"id":"39e8800a.b2141","type":"function","z":"cf294862.7e8b68","name":"Import","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = (parseFloat(fltView[0]) * 1.00361 + 36481.26).toFixed(2) ;\nmsg.topic = \"import\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":320,"wires":[["6860a00d.4d03","755cac29.d21844"]]},{"id":"6860a00d.4d03","type":"ui_text","z":"cf294862.7e8b68","group":"52e8e5ce.130db4","order":4,"width":0,"height":0,"name":"","label":"Energy Import","format":"{{msg.payload}} kWh","layout":"row-spread","x":580,"y":320,"wires":[]},{"id":"7a47858b.2a485c","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 230 Energy Exp","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"1","dataType":"InputRegister","adr":"74","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":180,"y":380,"wires":[["f8a5e4dd.65dd4"],[]]},{"id":"f8a5e4dd.65dd4","type":"function","z":"cf294862.7e8b68","name":"Export","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = (parseFloat(fltView[0]) * 1.00229 + 10274.41).toFixed(2);\nmsg.topic = \"export\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":380,"wires":[["386c164e.4bbc1a","755cac29.d21844"]]},{"id":"386c164e.4bbc1a","type":"ui_text","z":"cf294862.7e8b68","group":"52e8e5ce.130db4","order":5,"width":0,"height":0,"name":"","label":"Energy Export","format":"{{msg.payload}} kWh","layout":"row-spread","x":580,"y":380,"wires":[]},{"id":"9f8b2c57.5d5a3","type":"comment","z":"cf294862.7e8b68","name":"SDM120 Energy Meter","info":"","x":160,"y":460,"wires":[]},{"id":"a6cb9467.69a86","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 120 Voltage","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"2","dataType":"InputRegister","adr":"0","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":520,"wires":[["5a8f390e.8a6918"],[]]},{"id":"5a8f390e.8a6918","type":"function","z":"cf294862.7e8b68","name":"Voltage","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"voltage\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":380,"y":520,"wires":[["97ca0cdb.71eb2","7ee2add0.e052cc"]]},{"id":"97ca0cdb.71eb2","type":"ui_text","z":"cf294862.7e8b68","group":"519e323e.f5f804","order":1,"width":0,"height":0,"name":"","label":"Voltage","format":"{{msg.payload}} V","layout":"row-spread","x":560,"y":520,"wires":[]},{"id":"70f61194.d2be9","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 120 Current","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"2","dataType":"InputRegister","adr":"6","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":580,"wires":[["29bb0407.d78ee4"],[]]},{"id":"29bb0407.d78ee4","type":"function","z":"cf294862.7e8b68","name":"Current","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"current\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":380,"y":580,"wires":[["17f9b22e.8513be","7ee2add0.e052cc"]]},{"id":"17da4ae.2fe14b5","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 120 Power","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"2","dataType":"InputRegister","adr":"12","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":160,"y":640,"wires":[["a63fa0d5.975f4"],[]]},{"id":"a63fa0d5.975f4","type":"function","z":"cf294862.7e8b68","name":"Power","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0].toFixed(1));\nmsg.topic = \"power\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":640,"wires":[["9862b54a.ce90d8","7ee2add0.e052cc"]]},{"id":"9862b54a.ce90d8","type":"ui_text","z":"cf294862.7e8b68","group":"519e323e.f5f804","order":3,"width":0,"height":0,"name":"","label":"Power","format":"{{msg.payload}} W","layout":"row-spread","x":550,"y":640,"wires":[]},{"id":"162178a0.2804af","type":"modbus-read","z":"cf294862.7e8b68","name":"SDM 120 Energy Sol","topic":"","showStatusActivities":true,"logIOActivities":false,"showErrors":true,"unitid":"2","dataType":"InputRegister","adr":"72","quantity":"2","rate":"15","rateUnit":"s","delayOnStart":false,"startDelayTime":"","server":"8a72579f.202908","useIOFile":false,"ioFile":"","useIOForPayload":false,"x":180,"y":700,"wires":[["82d22530.e1375","8ec5d960.4ca1d8"],[]]},{"id":"82d22530.e1375","type":"function","z":"cf294862.7e8b68","name":"Solar","func":"var rawData = new ArrayBuffer(4);\nvar intView = new Uint16Array(rawData);\nvar fltView = new Float32Array(rawData);\n\nintView[0] = msg.payload[1]; //low\nintView[1] = msg.payload[0]; //high\n\nmsg.payload = parseFloat(fltView[0] * 1.00099 + 21326.51).toFixed(2);\nmsg.topic = \"solar\";\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.topic + \":\" + msg.payload}); \n\nreturn msg;","outputs":1,"noerr":0,"x":370,"y":700,"wires":[["f5ea2005.21f028","7ee2add0.e052cc"]]},{"id":"f5ea2005.21f028","type":"ui_text","z":"cf294862.7e8b68","group":"519e323e.f5f804","order":4,"width":0,"height":0,"name":"","label":"Energy Solar","format":"{{msg.payload}} kWh","layout":"row-spread","x":570,"y":700,"wires":[]},{"id":"17f9b22e.8513be","type":"ui_text","z":"cf294862.7e8b68","group":"519e323e.f5f804","order":2,"width":0,"height":0,"name":"","label":"Current","format":"{{msg.payload}} A","layout":"row-spread","x":560,"y":580,"wires":[]},{"id":"b4d90c81.c15988","type":"modbus-queue-info","z":"cf294862.7e8b68","name":"SDM120_queue","topic":"","unitid":"2","queueReadIntervalTime":"5000","lowLowLevel":"1","lowLevel":75,"highLevel":150,"highHighLevel":300,"server":"5642d1a0.fe87f8","errorOnHighLevel":false,"x":520,"y":900,"wires":[["ffd37a29.367e28"]]},{"id":"76179178.c5d938","type":"inject","z":"cf294862.7e8b68","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"x":149.00000762939453,"y":901.0000247955322,"wires":[["606911.9f3c9ef"]]},{"id":"606911.9f3c9ef","type":"change","z":"cf294862.7e8b68","name":"Reset queue","rules":[{"t":"set","p":"resetQueue","pt":"msg","to":"true","tot":"bool"}],"action":"","property":"","from":"","to":"","reg":false,"x":318.00000762939453,"y":901.0000114440918,"wires":[["b4d90c81.c15988"]]},{"id":"cddb4c9d.baf348","type":"function","z":"cf294862.7e8b68","name":"reset on HighHigh","func":"if(\"high high level reached\" === msg.state) {\n msg.resetQueue = true;\n return msg;\n}\n","outputs":1,"noerr":0,"x":392.8571548461914,"y":1031.1428470611572,"wires":[["b4d90c81.c15988","ee028367.4ac758"]]},{"id":"44043ade.580f5c","type":"catch","z":"cf294862.7e8b68","name":"Catch queue errors","scope":["b4d90c81.c15988"],"x":154.8571548461914,"y":1031.1428470611572,"wires":[["cddb4c9d.baf348"]]},{"id":"c3715613.168cc8","type":"comment","z":"cf294862.7e8b68","name":"Error handling","info":"","x":120.8571548461914,"y":986.1428470611572,"wires":[]},{"id":"ee028367.4ac758","type":"function","z":"cf294862.7e8b68","name":"Diagnostic input message structure","func":"// setting a global flag that the solar system is down\n\nmsg.payload = \"SDM120 modbus queue reached high level, resetting. (\" + msg.state + \")\";\nmsg.system = 4; // System id, use 1 for Dummy\n//msg.state = 1; // specify if the message is to change system status\nmsg.severity = 1; // 0: information, 1: warning, 2: error\nmsg.email = false; // if separate email should be sent\n//msg.emailtext = \"Clean up step of the SAIA log backup has failed\";\nreturn msg;","outputs":1,"noerr":0,"x":692.8571548461914,"y":1030.1428470611572,"wires":[["390172ec.6edbce"]]},{"id":"390172ec.6edbce","type":"link out","z":"cf294862.7e8b68","name":"","links":["13e089a7.73cb46"],"x":878.8571548461914,"y":1030.1428470611572,"wires":[]},{"id":"5f3cd465.3b374c","type":"catch","z":"cf294862.7e8b68","name":"Modbus read errors","scope":["70f61194.d2be9","162178a0.2804af","17da4ae.2fe14b5","a6cb9467.69a86","9f8b2c57.5d5a3"],"x":154.8571548461914,"y":1074.1428470611572,"wires":[["ee788b69.b501d8"]]},{"id":"ee788b69.b501d8","type":"function","z":"cf294862.7e8b68","name":"Diagnostic input message structure","func":"// setting a global flag that the solar system is down\n\nmsg.payload = \"SDM120 modbus error: \" + msg.error.message;\nmsg.system = 4; // System id, use 1 for Dummy\n//msg.state = 1; // specify if the message is to change system status\nmsg.severity = 1; // 0: information, 1: warning, 2: error\nmsg.email = false; // if separate email should be sent\n//msg.emailtext = \"Clean up step of the SAIA log backup has failed\";\nreturn msg;","outputs":1,"noerr":0,"x":443.8571548461914,"y":1074.1428470611572,"wires":[["237b54e8.3c67bc"]]},{"id":"237b54e8.3c67bc","type":"link out","z":"cf294862.7e8b68","name":"","links":["13e089a7.73cb46"],"x":629.8571548461914,"y":1074.1428470611572,"wires":[]},{"id":"ffd37a29.367e28","type":"debug","z":"cf294862.7e8b68","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","x":720.8571548461914,"y":899.1428470611572,"wires":[]},{"id":"8ec5d960.4ca1d8","type":"function","z":"cf294862.7e8b68","name":"Health check","func":"var devicename = \"sdm120\"; // Device name used for context variable\nvar system_id = 4; // System id number for diagnostic update\nvar online_threshold = 10; // Seconds between updates under which the device is considered online\nvar offline_threshold = 30; // Seconds between updates above which the device is considered offline\n\nvar temp = context.get(devicename+\"_update\");\nvar current = new Date();\nmsg.payload = \"No data\";\nmsg.warning = false;\nif (msg.topic!==\"timecheck\") {\n // Do not update the context if it is triggered by the check inject node\n context.set(devicename+\"_update\",current);\n}\nif (temp===undefined) {\n // this will be the case when node-red is booting up or redeployed\n context.set(devicename+\"_update\",current);\n}\n\nif (temp!==undefined) {\n current = current - temp;\n current = Math.floor(current/1000);\n var minute = Math.floor(current/60);\n var hour = Math.floor(minute/60);\n var day = Math.floor(hour/24);\n if (current>24*60*60) {\n msg.payload = \"Last update \" + day + \" days, \" + hour%24 + \" hours, \" + minute%60 + \" minutes, \" + current%60 + \" seconds ago\";\n } else if (current>60*60) {\n msg.payload = \"Last update \" + hour%24 + \" hours, \" + minute%60 + \" minutes, \" + current%60 + \" seconds ago\";\n } else if (current>60) {\n msg.payload = \"Last update \" + minute%60 + \" minutes, \" + current%60 + \" seconds ago\";\n } else {\n msg.payload = \"Last update \" + current%60 + \" seconds ago\";\n }\n\n if (context.get(devicename+\"_state\")!==1) {\n if (current<online_threshold) {\n msg.payload = \"SDM120 is now online\";\n msg.system = system_id; // System id, use 1 for Dummy\n msg.state = 1; // specify if the message is to change system status\n msg.severity = 0; // 0: information, 1: warning, 2: error\n //msg.email = true; // if separate email should be sent\n //msg.emailtext = \"\"; this a long text which goes into the email \n msg.warning = true;\n context.set(devicename+\"_state\",1);\n }\n } else {\n if (current>offline_threshold) {\n msg.payload = \"SDM120 is not transmitting\";\n msg.system = system_id; // System id, use 1 for Dummy\n msg.state = 99; // specify if the message is to change system status\n msg.severity = 2; // 0: information, 1: warning, 2: error\n //msg.email = true; // if separate email should be sent\n //msg.emailtext = \"\"; this a long text which goes into the email \n msg.warning = true;\n context.set(devicename+\"_state\",99);\n }\n }\n \n \n}\n\nnode.status({fill:\"blue\",shape:\"ring\",text:msg.payload});\n\nreturn msg;","outputs":1,"noerr":0,"x":390,"y":780,"wires":[["6cea0c6a.628304"]]},{"id":"ab080220.2b2ab8","type":"inject","z":"cf294862.7e8b68","name":"Check","topic":"timecheck","payload":"","payloadType":"date","repeat":"1","crontab":"","once":false,"x":140,"y":780,"wires":[["8ec5d960.4ca1d8"]]},{"id":"6cea0c6a.628304","type":"switch","z":"cf294862.7e8b68","name":"Update diag?","property":"warning","propertyType":"msg","rules":[{"t":"true"}],"checkall":"true","outputs":1,"x":585,"y":780,"wires":[["b3c5cd90.09b32"]]},{"id":"b3c5cd90.09b32","type":"link out","z":"cf294862.7e8b68","name":"","links":["13e089a7.73cb46"],"x":704.3015727996826,"y":779.571403503418,"wires":[]},{"id":"42364693.260b28","type":"modbus-queue-info","z":"cf294862.7e8b68","name":"SDM230_queue","topic":"","unitid":"1","queueReadIntervalTime":"5000","lowLowLevel":"1","lowLevel":75,"highLevel":150,"highHighLevel":300,"server":"5642d1a0.fe87f8","errorOnHighLevel":false,"x":520,"y":1160,"wires":[["dfb73b19.107e18"]]},{"id":"79d3e78d.d2d238","type":"inject","z":"cf294862.7e8b68","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":false,"x":149.00000762939453,"y":1161.0000247955322,"wires":[["6e42ae1a.04f558"]]},{"id":"6e42ae1a.04f558","type":"change","z":"cf294862.7e8b68","name":"Reset queue","rules":[{"t":"set","p":"resetQueue","pt":"msg","to":"true","tot":"bool"}],"action":"","property":"","from":"","to":"","reg":false,"x":318.00000762939453,"y":1161.0000114440918,"wires":[["42364693.260b28"]]},{"id":"40512c9f.ca430c","type":"function","z":"cf294862.7e8b68","name":"reset on HighHigh","func":"if(\"high high level reached\" === msg.state) {\n msg.resetQueue = true;\n return msg;\n}\n","outputs":1,"noerr":0,"x":392.8571548461914,"y":1291.1428470611572,"wires":[["42364693.260b28","2fe0a353.be909c"]]},{"id":"cb6ecebf.2473","type":"catch","z":"cf294862.7e8b68","name":"Catch queue errors","scope":["42364693.260b28"],"x":154.8571548461914,"y":1291.1428470611572,"wires":[["40512c9f.ca430c"]]},{"id":"438810a9.d9bb28","type":"comment","z":"cf294862.7e8b68","name":"Error handling","info":"","x":120.8571548461914,"y":1246.1428470611572,"wires":[]},{"id":"2fe0a353.be909c","type":"function","z":"cf294862.7e8b68","name":"Diagnostic input message structure","func":"// setting a global flag that the solar system is down\n\nmsg.payload = \"SDM120 modbus queue reached high level, resetting. (\" + msg.state + \")\";\nmsg.system = 4; // System id, use 1 for Dummy\n//msg.state = 1; // specify if the message is to change system status\nmsg.severity = 1; // 0: information, 1: warning, 2: error\nmsg.email = false; // if separate email should be sent\n//msg.emailtext = \"Clean up step of the SAIA log backup has failed\";\nreturn msg;","outputs":1,"noerr":0,"x":692.8571548461914,"y":1290.1428470611572,"wires":[["3ff9ed9f.31f832"]]},{"id":"3ff9ed9f.31f832","type":"link out","z":"cf294862.7e8b68","name":"","links":["13e089a7.73cb46"],"x":878.8571548461914,"y":1290.1428470611572,"wires":[]},{"id":"e85a26d5.e99ea8","type":"catch","z":"cf294862.7e8b68","name":"Modbus read errors","scope":["2d92317c.0c8ff6","7a47858b.2a485c","2a33780f.6c1dc8","dd502269.cf075","94d8cc20.dddda8","39fe0e66.c9799a"],"x":154.8571548461914,"y":1334.1428470611572,"wires":[["f880d888.e379f8"]]},{"id":"f880d888.e379f8","type":"function","z":"cf294862.7e8b68","name":"Diagnostic input message structure","func":"// setting a global flag that the solar system is down\n\nmsg.payload = \"SDM120 modbus error: \" + msg.error.message;\nmsg.system = 4; // System id, use 1 for Dummy\n//msg.state = 1; // specify if the message is to change system status\nmsg.severity = 1; // 0: information, 1: warning, 2: error\nmsg.email = false; // if separate email should be sent\n//msg.emailtext = \"Clean up step of the SAIA log backup has failed\";\nreturn msg;","outputs":1,"noerr":0,"x":443.8571548461914,"y":1334.1428470611572,"wires":[["93665473.948328"]]},{"id":"93665473.948328","type":"link out","z":"cf294862.7e8b68","name":"","links":["13e089a7.73cb46"],"x":629.8571548461914,"y":1334.1428470611572,"wires":[]},{"id":"dfb73b19.107e18","type":"debug","z":"cf294862.7e8b68","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","x":720.8571548461914,"y":1159.1428470611572,"wires":[]},{"id":"7ee2add0.e052cc","type":"function","z":"cf294862.7e8b68","name":"Build object","func":"watch_topic = \"solar\";\nvar output = {};\n\ncontext.set(msg.topic,msg.payload);\n\nif (context.get(\"voltage\")!==undefined) {\n output.voltage = context.get(\"voltage\");\n}\nif (context.get(\"current\")!==undefined) {\n output.current = context.get(\"current\");\n}\nif (context.get(\"power\")!==undefined) {\n output.power = context.get(\"power\");\n}\nif (context.get(\"solar\")!==undefined) {\n output.solar = context.get(\"solar\");\n}\nmsg.payload = output;\n\nif (msg.topic===watch_topic) {\n msg.topic = \"sdm120\";\n return msg;\n}","outputs":1,"noerr":0,"x":810,"y":600,"wires":[["d795a631.b276e8","e649422c.1df178"]]},{"id":"d795a631.b276e8","type":"debug","z":"cf294862.7e8b68","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","x":970,"y":600,"wires":[]},{"id":"e649422c.1df178","type":"mqtt out","z":"cf294862.7e8b68","name":"SDM120","topic":"sdm120","qos":"","retain":"","broker":"eb79ed91.8ce1a8","x":980,"y":540,"wires":[]},{"id":"755cac29.d21844","type":"function","z":"cf294862.7e8b68","name":"Build object","func":"watch_topic = \"export\";\nvar output = {};\n\ncontext.set(msg.topic,msg.payload);\n\nif (context.get(\"voltage\")!==undefined) {\n output.voltage = context.get(\"voltage\");\n}\nif (context.get(\"current\")!==undefined) {\n output.current = context.get(\"current\");\n}\nif (context.get(\"power\")!==undefined) {\n output.power = context.get(\"power\");\n}\nif (context.get(\"import\")!==undefined) {\n output.import = context.get(\"import\");\n}\nif (context.get(\"export\")!==undefined) {\n output.export = context.get(\"export\");\n}\nmsg.payload = output;\n\nif (msg.topic===watch_topic) {\n msg.topic = \"sdm230\";\n return msg;\n}","outputs":1,"noerr":0,"x":810,"y":260,"wires":[["88577a71.23e0a8","ae174f35.284c3"]]},{"id":"88577a71.23e0a8","type":"debug","z":"cf294862.7e8b68","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","x":970,"y":260,"wires":[]},{"id":"ae174f35.284c3","type":"mqtt out","z":"cf294862.7e8b68","name":"SDM230","topic":"sdm230","qos":"","retain":"","broker":"eb79ed91.8ce1a8","x":980,"y":200,"wires":[]},{"id":"8a72579f.202908","type":"modbus-client","z":"","name":"Serial_9600_8_N_1","clienttype":"serial","bufferCommands":true,"stateLogEnabled":false,"tcpHost":"127.0.0.1","tcpPort":"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB0","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","unit_id":"","commandDelay":30,"clientTimeout":2000,"reconnectTimeout":5000},{"id":"52e8e5ce.130db4","type":"ui_group","z":"","name":"SDM 230 Energy Meter","tab":"543f66f3.88086","order":2,"disp":true,"width":"6","collapse":false},{"id":"519e323e.f5f804","type":"ui_group","z":"","name":"SDM 120 Energy Meter","tab":"543f66f3.88086","order":2,"disp":true,"width":"6","collapse":false},{"id":"5642d1a0.fe87f8","type":"modbus-client","z":"","name":"Serial_9600_8_N_1","clienttype":"serial","bufferCommands":true,"stateLogEnabled":false,"tcpHost":"127.0.0.1","tcpPort":"502","tcpType":"DEFAULT","serialPort":"/dev/ttyUSB0","serialType":"RTU-BUFFERD","serialBaudrate":"9600","serialDatabits":"8","serialStopbits":"1","serialParity":"none","serialConnectionDelay":"100","unit_id":"","commandDelay":"30","clientTimeout":"2000","reconnectTimeout":"5000"},{"id":"eb79ed91.8ce1a8","type":"mqtt-broker","z":"","name":"Mosquitto","broker":"192.168.1.200","port":"1883","clientid":"","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthRetain":"false","birthPayload":"","closeTopic":"","closeQos":"0","closeRetain":"false","closePayload":"","willTopic":"","willQos":"0","willRetain":"false","willPayload":""},{"id":"543f66f3.88086","type":"ui_tab","z":"","name":"Modbus","icon":"memory","order":15}]
and this custom card:
and much insight from:
by Csongor Varga for my SDM120 (solar power) and SDM230 (grid import/export).
Hope it helps.