Publication 1766-RM001A-EN-P - October 2008
ASCII Instructions
381
•
Index value is less than 1 or greater than 82
•
Number value is less than 1 or greater than 82
•
Index value greater than the length of the Source string
The Destination string is not changed in any of the above error
conditions. When the ASCII String Manipulation Error bit (S:5/15) is set,
the Invalid String Length Error (1F39H) is written to the Major Error Fault
Code word (S:6).
AHL - ASCII Handshake
Lines
Instruction Type: output
The AHL instruction is used to set or reset the RS-232 Request to Send
(RTS) handshake control line for a modem. The controller uses the two
masks to determine whether to set or reset the RTS control line, or leave it
unchanged. The channel configuration must be set to ASCII.
Entering Parameters
Enter the following parameters when programming this instruction:
•
Channel
is the number of the RS-232 port, Channel 0.
•
AND Mask
is the mask used to
reset
the RTS control line. Bit 1
corresponds to the RTS control line. A value of “2” in the AND mask
resets the RTS control line; a value of “0” leaves the line unchanged.
•
OR Mask
is the mask used to
set
the RTS control line. Bit 1
corresponds to the RTS control line. A value of “2” in the OR mask
sets the RTS control line; a value of “0” leaves the line unchanged.
•
Control
is the control data file. See page 365.
EN
DN
ER
AHL
Ascii Handshake Lines
Channel
0
AND Mask
0002h
OR Mask
0000h
Control
R6:2
Channel Status
0000h<
Error
0<
AHL
Execution Time for the AHL Instruction
Controller
When Instruction Is:
True
False
MicroLogix 1400
26.5267 µs
2.9480 µs
TIP
Make sure the automatic modem control used by the port does not conflict
with this instruction.
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