HMS-EN2SE-R difficult setting up for MODBUS RTU RS485 communication in RSLogix 5000

We´re working to set up Communication with an external unit, that talks MODBUS RTU over RS485. We have a number of parameters that we´d like to read, and two that we would need to write to the unit.

The OEM supplier mentions the following

Read data instruction (0x03)
Requirement :
Node address (1 byte)
Function code : 0x03
Start address (2 byte) : 0000 - FFFF
Data amount (2 byte) : 1 ~ 125
Check digit (2 byte) CRC check

Answer
Node address (1 byte)
Function code : 0x03
The number of bytes (1 byte) - N = data amount * 2
The data content (N byte) - each data 2 bytes, the high data in the first, low data after
Check digit (2 byte) CRC check

Write data instruction (0x10)
Requirement
Node address (1 byte)
Function code : 0x10
Start address (2 byte) : 0000 - FFFF
Data amount (2 byte) : 1 ~ 120
Byte number (1 byte) n = data amount * 2
Data content (n byte)
Check digit (2 byte) CRC check

Answer
Node address (1 byte)
Function code : 0x10
Start address (2 byte) - 0000 - FFFF
The data amount (2 byte)
Check digit (2 byte) CRC check

– so, now to the problem - how do we actually set it up?

so, one parameter is for example called “Return Oil Temp”

In the OEM manual it is described as

Register address : 42012
Type : Read
Type of data : 16 bit signed binary

how do I actually generate the Query, and where is the value returned? i´ve tried lots of different ways, and dont get any data.

thanks in advance for any help!

Hello,

We do outline the transaction process within our User Manual found at this link:

You will need to set up the transaction and queries in the Configuration Manager. Once you configure the transactions, and download them to the PLC. You can run the maching, and monitor the data within the configuration manager.

You can use Node Monitor, Subnetwork Monitor, and Process Tags editor for diagnosing/monitoring data being exchanged.

I would advise reading through the manual as it will assist you setting up the communication, and verification of success.

Hi Kevin,

we´ve been studying this carefully, but it is not crystal clear as to how this ties into our OEM manual - we´ve been unable to get any kind of response out of the unit using the HMS unit. Is there any application engineer we can communicate directly with, who can also see what our OEM manual states? We are really struggling with this commissioning…

thanks!