Review on Industrial Modbus RTU Relay Module by Jeremy Jackz

This is a really good 8 channel Mobus RTU relay. Everything works as I expected. It responds to Modbus read and write coil commands and has non-standard coil switching code. It uses register 4000 hex to set the slave address. DIN rail and thru hole mounting options, it's much more professional than an exposed PCB and costs a few bucks more to have protection and DIN rail mounting. It has a status LED that flashes when the device is working, as well as transmit and receive LEDs. It comes with a power supply with a matching plug, but also has 5V screw terminal inputs if you want to hardwire it into an existing system that already has a 5V power system. I've been hooking up this unit for months. hooked up to my development machine and used to test my software and I often wished it had LEDs for relays. Spring. For some reason I took it today when it was on. and found out. IT DOES! There are very nice blue LEDs on the board just behind each relay pin. These are surface mount LEDs and you can't tell they're there when the power is off. but I didn't think to look for it because I didn't see any holes for the LED in the case. But actually there is a small gap between the case and the relay pins. and unless you have the device at an angle where you can't look directly into it, you'll never see the LEDs. Well, I was pleasantly surprised by the status LEDs, and now that I know they're there I can't help but see them. It was the only thing I wanted, and always has been, just hidden. I'm so happy that it has coil status LEDs that I thought this unit deserved a 5 star rating now. Great product at a reasonable price and it works very well. and it has status LEDs!