Incorrect modbus frame uniflair crah

[Renan_VASSEUR]

Hello all,

I am working on a CRAH, a uniflair one. Here are the information about the unit :

Hardware Factory

Model Number  0N-9582AC

Serial Number  SCB_139285

Hardware Revision  11

Network Management Card

Serial Number IA1712001377

Application Module

Name unflrle_l_e0001

version v6.4.4

APC OS (AOS)

Name aos 

Version v6.4.0

APC BOOT MONITOR

Name bootmon

Version v1.0.8

Controller Information

Serial Number  SCB_139285

Firmware Version 2.9

BIOS Version 6.27 

Boot Version 5.01

When trying to read any register, via modbus IP, the CRAH adds some bytes at the end that make the whole frame incorrect and ignored by my PLC (EBO AS-P 5.0.3 CP9)

Here raw modbus frame from modbuspoll

Tx:71-17:33:02.697-13 C3 00 00 00 06 01 03 00 01 00 01

Rx:72-17:33:03.084-13 C3 00 00 00 08 01 03 02 00 FA 00 00 46

The response should have stop at the end of FA

further exemple :

Tx:188-17:51:59.990-18 2C 00 00 00 06 01 03 00 02 00 01
Rx:189-17:52:00.390-18 2C 00 00 00 08 01 03 02 00 00 46 46 46

Tx:194-17:52:52.887-18 61 00 00 00 06 01 03 00 15 00 01
Rx:195-17:52:53.233-18 61 00 00 00 08 01 03 02 00 3C 46 46 46