Installation manual

Publication 1747-RM001G-EN-P - November 2008
ASCII Instructions 10-13
ASCII Handshake Lines
(AHL)
Use the AHL instruction to set or reset the RS-232 Data Terminal Ready
(DTR) and Request to Send (RTS) handshake control lines for your modem.
On a false-to-true transition, the processor uses the two masks to determine
whether to set or reset the DTR and RTS lines, or leave them unchanged. This
instruction will operate when the port is in either mode or is disabled.
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 type of mask used to reset the DTR and RTS control
lines. Bit 0 corresponds to the DTR line and bit 1 corresponds to the
RTS control line. A 1 at the mask bit causes the line to be reset; a 0
leaves the line unchanged. Note that mask values do not have a
one-to-one correspondence to the modem control lines.
• OR Mask is the type of mask used to set the DTR and RTS control
lines. Bit 0 corresponds to the DTR line and bit 1 corresponds to the
RTS control line. A 1 at the mask bit causes the line to be set; a 0 leaves
the line unchanged. Note that mask values do not have a one-to-one
correspondence to the modem control lines.
• Control is the area that stores the control register required to operate
the instruction.
• Channel Status displays the current status (0000 to 001F) of the
handshake lines for the channel, specified above. This field is display
only and resides in word 2 of the control element.
• Error displays the hexadecimal error code that indicates why the ER bit
was set in the control data file (R6). See page 10-24 for error code
descriptions.
EN
DN
ER
AHL
Ascii Handshake Lines
Channel 0
AND Mask 0FF03h
OR Mask 0FDEBh
Control R6:4
Channel Status 0000h
Error 0
AHL
Output Instruction
Fixed SLC
5/01
SLC
5/02
SLC
5/03
SLC
5/04
SLC
5/05
•••
TIP
Make sure the automatic modem control used by the
port, in system mode, does not conflict with this
instruction.