Thermocouple array data into Ignition

Does anyone have knowledge and experience capturing data from an array of thermocouples with Ignition without using a PLC?
I attempted to use the new MOXA 45MR series but even working with their tech support it was not successful and had to be abandoned.

For this specifc application I need to datalog 50 thermocouples. Because I am not controlling with any of them I am hopeful I can forgo the expensive PLC and specialty cards.

Okay, I really don’t know anything about these, but from browsing the MOXA site it seems like you’d need an ioThinx 4510 if you wanted to get at any of this I/O from Ignition.

Yeah, get the 4510 and un-abandon it. Should “Just Work” via Ignition’s Modbus TCP driver.

I should have been clearer. I abandoned the MOXA ioThinx 4510 and 45MR-6810 thermocouple modules because they would not report correct temperature measurement on their onboard webpage. The MOXA tech support could not resolve the issue. I decided if I couldn’t read temperatures at the module level there was no sense moving forward with passing bad data over to Ignition. And their tech support could not offer solution so the modules will be returned to them shortly. Meanwhile, I have a project that must move forward and I may have no choice but to go back to my tried and proven Rockwell CompactLogix and thermocouple input cards.

My original post had asked if anyone had knowledge or experience. It looks like Kevin is looking at the website for MOXA.
So, Phil, do you have first hand experience with these devices?

No, I was looking at the specs, too. I’m generally a fan of Moxa, so I’m astonished that they’ve botched this product.

Meanwhile, if you are going to buy Rockwell hardware but would rather skip the CPU, you might find my Ethernet/IP Class1 Communications Module helpful. Its scanner mode can work directly with pretty much any Ethernet/IP I/O gear. I test both Rockwell’s FlexIO and PointIO with it in my lab.

I appreciate the feedback.
But unfortunately it sounds like neither you or Kevin have experience or suggestion for other thermocouple input modules.
Hopefully others will chime in on this topic and offer additional insights.
Again, thanks.

Something like this might work. It is 8 channels so you would need at least 7 of them to cover 50 units.
They cost around $670.00 for 8 channels.

But they are Modbus TCP so in theory, you should be able to communicate with them through Modbus.
Thermocouple to Modbus Tcp (8-Channel)

Huh? I’ve deployed both Rockwell’s Point I/O and Flex I/O thermocouple inputs in past projects – with rock-solid results. Both of which are accessible without a Logix CPU via my module.

That said, @dcamp1’s suggestion is a lot cheaper. In theory, though. /:

My apologies Phil, that didn’t come across quite right. From the forum posts I am well aware of your vast experience. I’ll take a look at your module and perhaps give you a call to discuss.

Regarding theory, I’ve already expended too much time there.


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For applications with a large amount of monitoring thermocouples I have used the Watlow EZ Zone RM modules in the past, although I never have tested them for accuracy. As I recall it was quite a cost effective solution and I never heard any complaints from customers (like I have with Flex IO TC modules).

I used them with a CLogix PLC, but in theory they would also work the Ethernet IP ignition module described above.

Good Luck!


I have experience with thermocouples. Did you verify the sensors with another device? I know that poor wiring practices are mostly to blame for incorrect values. From input module to sensor the wire must be of the same type as the thermocouple. Are they grounded or ungrounded (grounded can pickup unwanted differences in potential) Is it possible the moxa was giving you incorrect values due to installation issues?

We monitor Automation Direct’s ProtosX IO over ModbusTCP on freezers. It works great! If the freezer gets too hot, Ignition alarms and sends out emails. No PLC required since it is not controlling anything. You do have to toggle a bit in the configuration to not timeout on the Protos IO otherwise if the Ethernet disconnects and times out it will not reconnect.
We also monitor 20 J type thermocouples this way for profiling heater platens over WiFi so the calibration tech does not need to find a network port to plug into. The IO head unit support hundreds of IO. You could do the same with WAGO, Beckhoff(they make ProtosX), OMRON, etc…
I have found that when skipping the PLC, Modbus TCP works better than Ethernet/IP since you get both master and slave protocols with the Modbus driver. The Ethernet/IP driver is intended to talk to PLCs and retrieve variables and not talk to IO. Modbus is an older simple protocol that does not care what it talks to. Mapping can be a headache however. The Protos setup tool helps with the mapping.

The MOXA IOTHINX4510 specs say that it will talk Modbus TCP. Its strange that it would not talk.

That is not true for the driver linked above. In fact, the complete opposite is true.

I was told by Inductive Automation that the driver was non deterministic and was intended to talk to PLC only while on a support call for something unrelated. I talk to several PLCs with the Ignition very reliably. I have not even tried talking to IO because of the previous statement. Have you had experience talking to IO, drives, etc (slaves) with the driver? That would be awesome if you could do that. How do you pull in the EDS file for mapping?

Yes. I am the author and maintainer of the driver. I have customers using this in production. EDS support is not automatic, and is described in the module documentation.