H-4
Communications Processor CP 541
EWA 4NEB 812 6188-02
STL
Explanation
OB 1
Segment 1
:JU FB 12
Name
:S 11=>12
ANST
:I 32.0
:
:JU FB 11
:R 11<=12
:
:BE
Cyclic program block
FB to send to station 12
Initiate sending with I 32.0
FB to receive from station 12
FB11
Segment 1
Name
:R 11<=12
:Q F 11.7
:BEC
:
:Q DB 11
:L DW 1
:T QB 32
:
:AN F 11.7
:S F 11.7
:BE
Receive block
Test whether L1 message present
If not, block end
Open receive mailbox
Output DR 1 to QB 32
Indication for operating system,
ready to receive again
FB12
Segment 1
Name
:S 11=>12
Des
:ANST I/Q/D/B/T/C: I BI/BY/W/D: BI
:Q F 12.7
:BEC
:
:Q =ANST
:AN F 0.0
:= F 0.1
:Q =ANST
:= F 0.0
:
:AN F 0.1
:BEC
:
:Q DB 12
:L KY 2,12
:T DW 0
:L IB 33
:T DW 1
:
:AN F 12.7
:S F 12.7
:
:BE
Send block
If send mail box blocked by operating
system, then block end
Initiation bit
Auxiliary flag for signal edge
Signal edge flag
Auxiliary flag for next cycle
If positive-going edge
Open send mailbox
Send 2 bytes to station 12
Store IB 33 in DR 1
Release send mailbox for operating
system
Program Examples