I am new to the Opto22 brand. In 2022, one of the field engineers in another business unit made a unilateral decision to move to the Opto22 brand to replace some of our Motorola Moscad SCADA kit. He bought 32 Groov epic R1 processors, 32x16 slots racks, 32xserial 485/232, 32xDI, and an 96xAI cards. Bare in mind that the non of the company remote well sites have ethernet, cellular or satellite connectivity due to their offshore locations and he didn’t purchase any DO or AO…absolutely amazing.
We have inherited the hardware and we will like to put these Groov into use instead of dumping the kit. We will like to configure the Groov Epic to be Modbus slave on the RS485 serial card to speak to the existing master RTU.
I have searched the forum and have found articles on Modbus/TCP and some mention of a Modbus slave integration kit but no success in RS485 Modbus Epic slave stuff. I have successfully communicate with the Groov using TCP, pulling a few IO values. But this in not what we want.
I am familiar with many of the 61131 programing tools from my Rockwell/Triconex and Honeywell background, but I intend to do the programming using PAC control. Codesys would be easy but I am trying to avoid spending more money on the Modbus SL license.
Q1: Out of the box can the Groov epic be configure to be a Modbus Slave using the GRV-CSERI-4? (I have seem mention how to set the communication handle for the serial port, but unaware of any task to process the incoming Modbus message)
Q2: Assuming Q1 is true, are there any examples of how setup the EPIC as a serial Modbus slave?
I would be grateful for any insight and links that gives us the opportunity to let opto22 platform add value to our oil and gas upstream business.
Quite the first post you have there!
Well done on digging deep and looking to use the kit vs throwing it out and trying to find another angle.
Have you ever used Node-RED?
I ask because depending on how many Modbus RTU registers you are looking to move back and forth, you might find it smoother than using the PAC Control Modbus toolkit.
Before we get too deep in the rabbit hole, lets ping @philip who has used the PAC Control tool kit as both slave and master a ton and see what he thinks might be the best option.
But, to quickly answer both questions.
Yes. You can use the tool kit to be a Modbus slave via the groov EPIC serial module.
Processing the incoming message is up to you. The data will be in the strategy.
Do you want do math on it, control something, store it, build a CSV file etc, its all up to you. The tool kit will get the register data, that’s its function done. What you do with it is up to you and your end result.
Yes, the toolkit has a readme doc in the download. Have you pulled it down and read it?
You don’t need to actually run it or such, just pull the zip and take a look.
I totally get your point about 32 CODESYS licenses, but think about it beyond the Modbus, what else do you need to do? Is there more than one developer going to be working on the system?
If there is more to this application than just reading a few Modbus RTU registers and if there are more devs than just you working on this application then some of the CODESYS features will more than pay for the up front license.
I haven’t ever used the slave part of the Modbus toolkit. I’ve used the built-in Modbus TCP server.
Anand, are you looking to simply use these as remote IO over Modbus RTU? If so, my approach would be to open the serial connection and listen for my slave Id and then “proxy” the request to the Modbus TCP server on localhost. It would be a fairly small PAC Control program to make that happen, though you would need to know how to parse a bit of the Modbus packet.
Many thanks for providing encouragement and the pointers.
Using the Modbus Integration Kit: pac-int-mb-slave, I am able to get a Modbus master (ScanBus-BR) to query data from the Groov Epic. (minor configuration change on the comhandle was required)
Now the fun really starts. We are aiming to use the Groov Epic as a BPCS to monitor and control a four well gas lift cluster. Also we will attempt to integrate the Groov Epic 485 serial to a VolleyBoast HL-1 universal LoRaWAN bridge endpoint.
