Cannot have Zigbee2MQTT connecting to SLZB-06M

[lucj (LJ)]

Hello,
I’m new to Home Assistant. I’ve installed it on a RPI on my LAN. and also installed Mosquitto and Zigbee2MQTT addons. I have a SMLight SLZB-06M (firmware version is 2.7.1) but I do not manage to have Zigbee2MQTT connect to this one.
My configuration is this:

data_path: /config/zigbee2mqtt
socat:
  enabled: false
  master: pty,raw,echo=0,link=/tmp/ttyZ2M,mode=777
  slave: tcp-listen:8485,keepalive,nodelay,reuseaddr,keepidle=1,keepintvl=1,keepcnt=5
  options: "-d -d"
  log: false
mqtt: {}
serial:
  port: tcp://192.168.1.17:6638
  baudrate: 115200
  adapter: ember
  disable_led: false
advanced:
  transmit_power: 20

On Zigbee2MQTT side, I get those logs:

[08:29:33] INFO: Preparing to start...
[08:29:33] INFO: Socat not enabled
[08:29:34] INFO: Starting Zigbee2MQTT...
Starting Zigbee2MQTT without watchdog.
[2025-04-25 08:29:37] info: 	z2m: Logging to console, file (filename: log.log)
[2025-04-25 08:29:37] info: 	z2m: Starting Zigbee2MQTT version 2.2.1 (commit #unknown)
[2025-04-25 08:29:37] info: 	z2m: Starting zigbee-herdsman (3.4.11)
[2025-04-25 08:29:38] info: 	zh:ember: Using default stack config.
[2025-04-25 08:29:38] info: 	zh:ember: ======== Ember Adapter Starting ========
[2025-04-25 08:29:38] info: 	zh:ember:ezsp: ======== EZSP starting ========
[2025-04-25 08:29:38] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-04-25 08:29:38] info: 	zh:ember:uart:ash: Socket ready
[2025-04-25 08:29:38] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-04-25 08:29:38] error: 	zh:ember:uart:ash: Port Error: read ECONNRESET
[2025-04-25 08:29:38] info: 	zh:ember:uart:ash: Port closed.
[2025-04-25 08:29:40] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-04-25 08:29:40] info: 	zh:ember:uart:ash: Socket ready
[2025-04-25 08:29:40] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-04-25 08:29:41] error: 	zh:ember:uart:ash: Port Error: read ECONNRESET
[2025-04-25 08:29:41] info: 	zh:ember:uart:ash: Port closed.
[2025-04-25 08:29:43] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-04-25 08:29:43] info: 	zh:ember:uart:ash: Socket ready
[2025-04-25 08:29:43] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-04-25 08:29:43] info: 	zh:ember:uart:ash: Port closed.
[2025-04-25 08:29:45] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-04-25 08:29:45] info: 	zh:ember:uart:ash: Socket ready
[2025-04-25 08:29:45] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-04-25 08:29:46] error: 	zh:ember:uart:ash: Port Error: read ECONNRESET
[2025-04-25 08:29:46] info: 	zh:ember:uart:ash: Port closed.
[2025-04-25 08:29:48] info: 	zh:ember:uart:ash: ======== ASH Adapter reset ========
[2025-04-25 08:29:48] info: 	zh:ember:uart:ash: Socket ready
[2025-04-25 08:29:48] info: 	zh:ember:uart:ash: ======== ASH starting ========
[2025-04-25 08:29:49] error: 	zh:ember:uart:ash: Port Error: read ECONNRESET
[2025-04-25 08:29:49] info: 	zh:ember:uart:ash: Port closed.
[2025-04-25 08:29:50] error: 	z2m: Error while starting zigbee-herdsman
[2025-04-25 08:29:50] error: 	z2m: Failed to start zigbee-herdsman
[2025-04-25 08:29:50] error: 	z2m: Check https://www.zigbee2mqtt.io/guide/installation/20_zigbee2mqtt-fails-to-start_crashes-runtime.html for possible solutions
[2025-04-25 08:29:50] error: 	z2m: Exiting...
[2025-04-25 08:29:50] error: 	z2m: Error: Failed to start EZSP layer with status=HOST_FATAL_ERROR.
    at EmberAdapter.initEzsp (/app/node_modules/.pnpm/[email protected]/node_modules/zigbee-herdsman/src/adapter/ember/adapter/emberAdapter.ts:672:19)
    at EmberAdapter.start (/app/node_modules/.pnpm/[email protected]/node_modules/zigbee-herdsman/src/adapter/ember/adapter/emberAdapter.ts:1538:24)
    at Controller.start (/app/node_modules/.pnpm/[email protected]/node_modules/zigbee-herdsman/src/controller/controller.ts:136:29)
    at Zigbee.start (/app/lib/zigbee.ts:69:27)
    at Controller.start (/app/lib/controller.ts:104:13)
    at start (/app/index.js:149:5)

And on the SLZB side I get this

taskZB | Client limit has been reached!

I do not really understand as I do not have any other devices connected from what I know.
Any idea of the possible causes of this problem ?
Thank you for you help.

[fleskefjes]

When Z2M is stopped, how many clients do you see in the web gui?

[lucj (LJ)]

Hello, I have one client connected, hum… I don’t know what this one is.

[n1976jmk]

And on the SMLight webpage under the modes section, you don’t have the esp Bluetooth mode and or thread radios turned on? Just zigbee coordinator.

Only zigbee coordinator mode?

Also, from your HA, 192.168.1.17, that’s the IP of your SMLight? Then you have that SMLight IP reserved in your router so no other devices can you use it? And in the web gui of the SmLight you have it set to use a static ipv4 addy (ending in 1.17 to confirm).

In addition, your HA instance, in the network section of ‘system’, you set a static ipv4 IP address? And have that reserved in your router?

Thanks!

[lucj (LJ)]

Yes, I only have Zigbee coordinator activated.

192.168.1.17 is the IP of the SMLight, this has been given by DHCP.
192.168.1.32 is the IP of HA, also given by DHCP

[n1976jmk]

I’d switch both to use static IPs only, then reserve the addresses in your router. Have the static IP be what the addresses are now so less config changes needed in HA.

Then restart the router, then restart your HA and SMLight.

I use static for my HA and SMLight and never had this issue.

This will help from another device connecting to it.

Please let us know.

You got this!

[fleskefjes]

Make sure you don’t have ZHA installed and using the coordinator. If you have 1 client connection even with Z2M stopped something is connecting to port 6638 on the SLZB.

[lucj (LJ)]

Thank you. I’ll try to get rid of this Client limit thing and I’ll probably cleanup my network settings static IPs

[n1976jmk]

Never stupid question, I only started with HA in October 2024 so I always love to return favor and help others like they help me. I only know 0.5% of HA so I definitely still learning too.

But to answer your ZHA running or not question.

Go to HA, then ‘settings’, then ‘devices & services’.

Look through that list of installed devices and services (it’s in alphabetical order) on that page, you don’t see ZHA listed. If you do see it listed. Then delete it and restart your HA instance afterwards.

[lucj (LJ)]

Stupid question… how can I know ZHA is installed ?
If I reboot SLZB I should not have any connection, right ? But in my case I can even see a client connected after reboot.

[lucj (LJ)]

Thank you. This is what I have, so no ZHA here.

[francisp (Francis)]

ZHA: (Zigbee Home Automation)

[lucj (LJ)]

Silly me I didn’t know it was that item.
Thank you I’ll get rid of this and see if it’s better.

[n1976jmk]

It’s gotta be better.
.just please make sure to restart your HA afterwards. I’d also resrtart your SMLight afterwards as well

[lucj (LJ)]

Thanks a lot for your help, this is much better indeed

[n1976jmk]

hi Lucj, GREAT TO HEAR! to help other people with similar problems in the future, can you please mark your post as resolved and you select the comment which fixed the issue. thanks!