Serial Communications 3104
REC XXXXX 3-32
Å 01H 10H 00H 7CH 00H 02H 80H 10H
Exceptions :
The instrument handles the following exceptions :
Illegal address exception code = 02 address is not correct or number of
registers overlaps the max limit (42).
Illegal value exception code = 03 value is out of the limits or protected.
3.9 Allen Bradley DF1 (PLC-5)
The DF1 is a propietary protocol of Allen-Bradley. The protocol has been implemented
according to : Allen-Bradley “Reference Manual – Data Highway / Data Highway Plus
Protocol and Command Set”
The commands used to read or write the registers are : typed read (code 68h) and typed
write (67h).
3.9.1 Read Registers
Connect message
This message must be sent from Host to Slave before a request of sending data can be
performed.
HOST (PLC)
SLAVE (3104)
DLE (10H) Æ
SOH (01H)
ADDRESS OF SLAVE
DLE (10H)
STX (02H)
ADDRESS OF SLAVE
ADDRESS OF HOST
COMMAND (OFH)
STS (00H)
TMS (xxH)
TMS (xxH)
FNC (68H)
PACKET OFFSET (LOW)
PACKET OFFSET (HIGH)
TOTAL TRANS (LOW)
TOTAL TRANS (HIGH)
ADDRESS OF DATA (FIRST BYTE)
ADDRESS OF DATA (SECOND BYTE)
ADDRESS OF DATA (THIRD BYTE)
ADDRESS OF DATA (FOURTH BYTE)
SIZE OF DATA IN ELEMENTS (LOW)
SIZE OF DATA IN ELEMENTS (HIGH)
DLE (10H)
ETX (03H)
BCC Æ
Å DLE (10H)
Å ACK (06H)
Ask data :
This message is sent from the Host to the Slave to request a certain number of data :
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