Publication 1762-RM001C-EN-P
20-20 ASCII Instructions
Instruction Operation
This instruction executes on a true rung.
The following conditions cause the controller to set the ASCII String
Manipulation Error bit (S:5/15):
•
Source string length is less than 1 or greater than 82
•
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. (For the
1764-LRP only, you can select either Channel 0 or Channel 1.)
EN
DN
ER
AHL
Ascii Handshake Lines
Channel 0
AND Mask 0002h
OR Mask 0000h
Control R6:2
Channel Status 0000h<
Error 0<
AHL
Table 20.21 Execution Time for the AHL Instruction
Controller When Instruction Is:
True False
MicroLogix 1200 Series B, FRN 3 or later 109.4
µ
s 11.9
µ
s
MicroLogix 1500 Series B, FRN 4 or later 89.3
µ
s 10.8
µ
s
NOTE
Make sure the automatic modem control used by the port
does not conflict with this instruction.