Moeller MV4 Series - Data Transfer Protocol; Control Characters; Data Format

Communications Card Description ZB4-601-IF1, ZB4-609-IF1 4-41
Moeller 07/01 AWB-C2700-1347GB
8.16.1 Data transfer protocol
The data exchange between the PLC and the ZB4-601/609-IF1 is carried out only on request.
Two different commands are provided for this, which are each initiated by an STX (02
h
):
40
h
: Send (ZB4-601/609-IF1 sends data to the PLC)
44
h
: Receive (ZB4-601/609-IF1 expects data from the PLC)
The Send command is only initiated by the ZB4-601/609-IF1 if new values are detected from the application
for the PLC data.
The Receive command is processed normally by the ZB4-601/609-IF1 cyclically (approx. every 100 ms)
each time data is polled by the PLC from the application.
When using the TP1 protocol, each data word is transferred individually of the TP2 protocol data blocks
(n-bytes).
8.16.2 Control characters
RECEIVE : 44
h
Data direction SPS –> ZB4-601/609-IF1
SEND : 40
h
Data direction ZB4-601/609-IF1 –> SPS
STX : 02
h
Start transmission
ETX : 03
h
End transmission
NAK : 15
h
Command or data invalid
ACK : 06
h
Command or data valid
CR : 0D
h
String end (only for TP1 protocol)
8.16.3 Data format
With the TP1 protocol all data words and addresses are transferred as ASCII hex strings.
Addresses are 3 fixed bytes 000
h
to 800
h
Values are 4 fixed bytes 0000
h
to FFFF
h
Each of these hex strings are completed with a CR (0dh).
Examples:
Decimal Hexadecimal Hexadecimal String
2368 0940
h
30
h
33
h
34
h
30
h
17238 4356
h
34
h
33
h
35
h
36
h
–15364 C3FC
h
43
h
33
h
46
h
43
h
When using the TP2 protocol, all data words and addresses are transferred as 2 bytes with the HI byte
being transferred before the LO byte.
The TP2 protocol is considerably more efficient than the TP1 protocol. However, it is more difficult to
implement the TP2 protocol in some programmable controllers.