I’m looking for a good, quick source for a for ready-to-use modbus cable to connect a Solark15k inverter RS485 to a USR-TCP232-410S modbus TCP converter which has a terminal bloc that just takes the two power wires and a ground. I can only seem to find ones with a USB end. Would this DMX cable work or please let me know what you’ve been able to get that works: RJ45 Female to Bare Wire DMX Control Cable - Ecolocity LED
I don’t have access to any crimping tools, so something plug-and-play is highly desirable. Many thanks in advance!
Looks like I’ll have to build my own, I guess out of a pass-through CAT6 RS484 RJ45 cable and cut off one of the ends and figure out the wiring to the terminal block, which is pretty well documented in various places.
OK, got it working. Took a standard passthrough RS485 cable and cut off one end. Pin 7 (brown/white stripe) goes to terminal A on modbus device, pin 8 (brown) to terminal B , and pin 6 (green) to Ground. Restarted HA and it all came alive. There are some drop outs which might be from insufficient shielding or lack of 120 ohm termination or who knows what, but it’s mostly sending data and HA is picking it up properly. Attached is the RS485 configuration on the modbus unit.
I did not have to do anything on the Solark end other than plug in the RJ45 cable to the modbus port. The Solark in question is the model 15k-2P-N, so there may be variations for other inverters. Check the Solark manual for details. Purportedly, the Battery CANbus port can also be used, as the battery uses different pins.
P.S. Have not seen any logged errors since Dec. 29. Occasionally, the display shows “unavailable” but it seems to correct itself presently. Hard to tell from the graphs if there are actual small gaps or it’s just their limited resolution. The huge gaps from earlier no longer seem to be showing up, which is encouraging.
Gaps now showing up primarily at night. More research needed …
Tried foil shielding with little to no effect. May have to try a better shielded cable at a future date and.or changing modbus parameters. Anyone have any suggestions for the modbus settings?