User guide

Communication protocol Serie30 Page 8/37
3.3.2.2 Exception errors
The message has been received correctly (no transmission error has occurred), but the transmitted function number and/or the
parameters are invalid. The slave responds with an exception error, unless the message has been received in broadcasting
mode.
The message transmitted as a response by the slave has the following format:
DevAddr
1
Function
code
Exception
code
KELLER:CRC16_H
MODBUS:CRC16_L
KELLER:CRC16_L
MODBUS:CRC16_H
4 types of exception errors are defined :
non-implemented function 1
incorrect parameters 2
erroneous data 3
initialisation (only KELLER bus) 32
Exception error 32 occurs when the device is started up anew and initialisation has not been carried out. This happens every
time the device is connected anew after a break in the power supply.
only MJK bus
again