# Protocol character in response:Modbus to ABEthernet /PLC-5 Ser.C Rev.J **URL:** \ **Category:** Digi One IA/IAP\ **Created:** [April 25, 2009, 4:59pm UTC](https://forums.digi.com/t/protocol-character-in-response-modbus-to-abethernet-plc-5-ser-c-rev-j/7478 "2009-04-25T16:59:40Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![paisengineer](https://avatars.discourse-cdn.com/v4/letter/p/3be4f8/32.png) [@paisengineer](https://forums.digi.com/u/paisengineer)\ **Post date:** [April 25, 2009, 4:59pm UTC](https://forums.digi.com/t/protocol-character-in-response-modbus-to-abethernet-plc-5-ser-c-rev-j/7478/1 "2009-04-25T16:59:40Z")
Modbus response for first N7 register places CSP header data (Value 0x42) into the response 2nd byte. Scanning PLC-5 register N7:2. Modbus scan register is 2. N7:2 value is x50 (decimal 80). N7:4 value is x20 (decimal 32). Response to Modbus poll: 01.03.00.02.00.01.25.CA. is: 01.03.02.50.42.04.75. Response to poll:01.03.00.02.00.02.65.CB. is: 01.03.04.50.42.20.00.52.E7. ia target is plc5. Should this be fixed in the ia table for the abethernet protocol or in the serial section? ---
**Author:** ![lynnl](https://avatars.discourse-cdn.com/v4/letter/l/22d042/32.png) [@lynnl](https://forums.digi.com/u/lynnl)\ **Post date:** [April 27, 2009, 2:02pm UTC](https://forums.digi.com/t/protocol-character-in-response-modbus-to-abethernet-plc-5-ser-c-rev-j/7478/2 "2009-04-27T14:02:07Z")
I don’t really understand the question? Make sure you use the latest firmware, which is the G2. Digi doesn’t own a PLC5, so support for that command-set has always been (per the Readme file) limited to how a ControlLogix likes the PLC5 requests formed. However, for firmware G2 a large customer worked to confirm the PLC5 support. I forget the details, but there was some off-by-one issue fixed related to how the PLC5 response (which was a different form than how the CLgx replied) was parsed.