Instruction Manual

Section 4: Commissioning
10/08 116 51207 Revision 1
4.12.8 Function 16: Writing n Successive Words
Command Device
address
Function
number
Address
of 1st
word
Number
of words
Number
of bytes
Value of
words
CRC 16
1 byte 1 byte 2 bytes 2 bytes 1 byte n bytes 2 bytes
Range 0...127 16 0...63 1...64 2...128 / \
MSB LSB MSB - - - - - - - MSB LSB
1st word last
Reply Device
address
Function
number
Address of
1st word
Number of
words
CRC 16
1 byte 1 byte 2 bytes 2 bytes 2 bytes
If the address is out of the permissible range (0...63), an error message is sent as a reply (the
address plus the number of bytes must not exceed 64).
Example of function 16 for writing the limit_1 switch-on point using value 893:
Command 1 16 0 48 0 2 4 0 0 3 125 CR
C
CR
C
Reply 1 16 0 48 0 2 CR
C
CR
C
The individual bytes are shown.
4.12.9 MODBUS / J-BUS Error Messages
If a command was transmitted correctly, but cannot be executed because e.g. the address is too
high, an error message is sent as a reply to the command.
The error message has the following format:
Device
address
Function
number +128
Error number CRC 16
1 byte 1 byte 1 byte 2 bytes
The 2nd byte contains the received function number; the most significant bit is set additionally.
Meaning of the error number:
1 The function number is unknown
2 The address is out of the permissible range
3 The data format is faulty (e.g. more data than specified in the number were
written)
Example of an error message which was generated by an invalid function number.
Command 1 9 0 0 0 0 CRC CRC
Reply 1 137 1 CRC CRC
The individual bytes are shown.