Will need to control 30 relays preferably “directly” through Ignition and I’m wondering if anyone has done similar and can provide assistance/ideas?
Considering something like the Ethernet relay module from Numato https://numato.com/docs/32-channel-ethernet-relay-module/
Numato supplies commands that can be used via telnet for control. Before buying this or another unit, I am wondering about using Python from Ignition (possibly referencing some functions in a package) and use the Python Telnet client library to send commands. Also wondering if I could just use the scripting function system.util.excecute?
Does anyone have experience with this, or perhaps a completely different solution that you can share?
Depends on what you need to happen if the connection to the device is broken. Whether by loss of network, or Ignition shutdown, or unexpected crash of Ignition or its server. If the equipment is safe to leave in its last state indefinitely, something like the referenced device is fine, and you just have to custom script access to its features. If the outputs need to turn off or otherwise go to a safe state in the event of a comms loss, you need a device with a heartbeat feature and/or a device that understands a modern I/O scanner protocol. The latter is currently available for the Ethernet/IP protocol in Ignition via my Ethernet/IP Class 1 Communications module.
As mentioned above it all depends on what the relays are controlling. Also be aware of the emergency stop regulations and what class you need etc. If its switching a water sprinkler for example differs from controlling a moving machine.
I would probably look at Modbus TCP there is all kinds of Modbus I/O control modules on the web that can do what you ask.
I have used similar relay modules as the one you provide in the link and they have worked very well for me also.
They reason I would probably use a Modbus Tcp I/O module is because they come in "Digital In, Digital Out(Relay), Analog In, Analog Out.
Just an Idea.
A few of them even have watchdog timers for comm loss, like Advantech's ADAM-6050.
Thanks for all these items to consider. I’m in the initial stages of deciding how to go about this. I hadn’t considered a broken connection that could leave things in an undesirable state and I need to determine if that will be a real problem in this case.
Phil, I’m not quite ready to get going on this project just yet, but is it possible at some point to evaluate your module on a short time basis perhaps before purchasing?
Sure. PM me or email me when you're ready.