Siemens SIMATIC S5 CP 523 Manual page 239

Summary
"Send fixed-length message frame" or send with 3964(R) ( 7.6.1)
Table A-9. Transfer Memory Assignments for "Send Fixed-Length Message Frame"
(CPU to CP)
Byte
0 Job number for "Coordinate data transfer"
1 "Send message frame" identifier
2+3 Send length in bytes
4-7 Not significant
"Send frame with end-of-text character" ( 7.6.2)
Table A-10. Transfer Memory Assignments for "Send Message Frame with
Byte
0 Job number for "Coordinate data transfer"
1 "Send message frame" identifier
2+3 Send length in bytes
4 2nd end-of-text character
5 1st end-of-text character
6+7 Not significant
"Receive message frame" ( 7.7)
Table A-11. Transfer Memory Assignments for "Receive Message Frame" (CPU to CP)
Byte
0 Job number for "Coordinate data transfer"
1 "Receive message frame" identifier
2-7 Not significant
A-10
Meaning
End-of-Text Characters" (CPU to CP)
Meaning
no 2nd end-of-text character
Meaning
CP 523
Value Range
A0
H
01
H
0001 to 0100
H H
00 to FF
H H
Value Range
A0
H
01
H
0000
H
01 to FF
H H
00
H
01 to FF
H H
00 to FF
H H
Value Range
A0
H
80
H
00 to FF
H H
EWA 4NEB 811 6044-02a