Hello All,
My name is Austen, and I am working on a project for a plastics extrusion plant that deals with a lot of thermocouples and other things. The type of TCs being used are type J thermocouples.
We are having an issue with a Moxa ioLogik E1262 TC Series Ethernet Remote I/O Module. This module transmits the temperature readings into an Allen Bradley CompactLogix 5069-L306ER as a Remote I/O device with an EDS file applied to Studio 5000.
The problem we are having is our readings from the Moxa are jumping +- 5,6,7 degrees when activating production mode in the program. What production mode activates is a cutter motor to cut the product as it is extruding. When production mode is not activated, our readings are correct and very stable.
Attachment 1 'Moxa1' is a screenshot of the jumping we trended in Studio 5000.
The original way these TCs were read was by a Eurotherm controller. This controller oversaw temperature control as well as transmitted the temperature to an Allen Bradley SLC500 controller through Modbus.
We believe there is some type of noise interfering with our readings that we just cannot seem to remove. We have gone through multiple tests to try to remove this noise with no luck. Because we could not find a solution to this problem in a timely manner, we rewired the TCs to the Eurotherm controllers to see if they were jumping. The readings are perfect and rock solid when production mode was active. The line is running using the Eurotherms right now to allow us to continue testing and continue making product.
The TC wire is just 2 solid wires covered in a plastic sheath. The TC wire is running through conduit with 120VAC and some shielded analog wire. At a certain point this conduit goes to a junction box where the TC wire again goes through another piece of conduit where it is introduced to 480VAC. That 480VAC powers the cutter motor.
The Allen Bradley CompactLogix and the Moxa Modules are powered with 24VDC. There is a total of 5 devices on the 24VDC PS. 3 Moxa Analog Input modules, 1 Moxa TC module, and 1 CompactLogix.
Attachment 2 'Moxa2' is a photo of the CompactLogix and the Moxa modules.
Our first test we attempted was putting a UPS between the 120VAC powering the 24VDC power supply to power the Moxas and CompactLogix.
Our second test was powering just the Moxa TC module with a different 24VDC power supply and the UPS.
Our third test was to try running twisted-shielded TC extension wire through the conduit and connecting the TC to it to see if it would remove the noise.
Each test has failed, and we have run out of ideas.
There is a total of 5 lines with this process at the end of each line in the plant. I am going to attempt testing all lines and see if it is common throughout or if it is secluded to just one line.
We have been in contact with Moxa and awaiting answers.
Would anyone have any additional thoughts as to what could be causing this or what we could test next? I hope my explanation of the issue painted a decent picture, but please ask me any questions if something doesn't make sense.
My name is Austen, and I am working on a project for a plastics extrusion plant that deals with a lot of thermocouples and other things. The type of TCs being used are type J thermocouples.
We are having an issue with a Moxa ioLogik E1262 TC Series Ethernet Remote I/O Module. This module transmits the temperature readings into an Allen Bradley CompactLogix 5069-L306ER as a Remote I/O device with an EDS file applied to Studio 5000.
The problem we are having is our readings from the Moxa are jumping +- 5,6,7 degrees when activating production mode in the program. What production mode activates is a cutter motor to cut the product as it is extruding. When production mode is not activated, our readings are correct and very stable.
Attachment 1 'Moxa1' is a screenshot of the jumping we trended in Studio 5000.
The original way these TCs were read was by a Eurotherm controller. This controller oversaw temperature control as well as transmitted the temperature to an Allen Bradley SLC500 controller through Modbus.
We believe there is some type of noise interfering with our readings that we just cannot seem to remove. We have gone through multiple tests to try to remove this noise with no luck. Because we could not find a solution to this problem in a timely manner, we rewired the TCs to the Eurotherm controllers to see if they were jumping. The readings are perfect and rock solid when production mode was active. The line is running using the Eurotherms right now to allow us to continue testing and continue making product.
The TC wire is just 2 solid wires covered in a plastic sheath. The TC wire is running through conduit with 120VAC and some shielded analog wire. At a certain point this conduit goes to a junction box where the TC wire again goes through another piece of conduit where it is introduced to 480VAC. That 480VAC powers the cutter motor.
The Allen Bradley CompactLogix and the Moxa Modules are powered with 24VDC. There is a total of 5 devices on the 24VDC PS. 3 Moxa Analog Input modules, 1 Moxa TC module, and 1 CompactLogix.
Attachment 2 'Moxa2' is a photo of the CompactLogix and the Moxa modules.
Our first test we attempted was putting a UPS between the 120VAC powering the 24VDC power supply to power the Moxas and CompactLogix.
Our second test was powering just the Moxa TC module with a different 24VDC power supply and the UPS.
Our third test was to try running twisted-shielded TC extension wire through the conduit and connecting the TC to it to see if it would remove the noise.
Each test has failed, and we have run out of ideas.
There is a total of 5 lines with this process at the end of each line in the plant. I am going to attempt testing all lines and see if it is common throughout or if it is secluded to just one line.
We have been in contact with Moxa and awaiting answers.
Would anyone have any additional thoughts as to what could be causing this or what we could test next? I hope my explanation of the issue painted a decent picture, but please ask me any questions if something doesn't make sense.
