Instruction Manual

Section 4: Commissioning
10/08 113 51207 Revision 1
4.12.2 Function 1 or 2: Reading n Bits
Command Device
address
Function
number
Address
of 1st bit
Number
of bits
CRC 16
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Range 1...127 1, 2 0,8,16... 8,16,24.
..
The bit address must always be the 1st bit of a byte. The number of bits to be read may not be
smaller than 8 and must be a multiple of 8.
Reply Device
address
Function
number
Number of
read bytes
Value of
1st byte
Value of
2nd byte ..
Value of
last byte
CRC 16
1 byte 1 byte 1 byte 1 byte 1 byte 1 byte 2 bytes
8th ...
1st
bit
last bit
If the address of a bit to be read is out of the permissible range (0...127), an error message is sent
as a reply (the address plus the number of bits must not exceed 128).
Example of function 1 for reading the status bits of the scale.
Command 1 1 2 32 0 8 CRC CRC
Reply 1 1 1 X CRC CRC
The read byte X Bit 0 = bit 32 of SPM = ADC error
is interpreted as follows: Bit 1 = bit 33 of SPM = above Max (maximum capacity)
:
Bit 6 = bit 38 of SPM = weight is stable
Bit 7 = bit 39 of SPM = weight is below zero or above Max
4.12.3 Function 3 or 4: Reading n Successive Words
Command Device
address
Function
number
Address of
1st word
Number of
words
CRC 16
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Range 1...127 3,4 0...63 1...64
Reply Device
address
Function
number
Number of
bytes
Number of
words
CRC 16
1 byte 1 byte 1 byte n bytes 2 bytes
MSB LSB MSB - - - - - - MSB LSB
1
st
word last word
If the address of one of the words to be read 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 3 for reading a gross weight (D8 = W16) of 893 kg
Command 1 3 0 16 0 2 CRC CRC
Reply 1 3 4 0 0 3 125 CRC CRC
The individual bytes are shown.