Envoy ACP/XF Application Programming Manual

EnvoyACP/XF and the Application Task
EnvoyACP/XF Application Programming Manual–132179
1-20
Your Application and V.25 bis
Call Collisions
Outgoing and incoming calls may collide, but only on rare occasions. The following
considerations may affect how you decide to handle collisions:
•
Since the incoming call is unknown information, you may wish to give priority to
the incoming call. You can transmit the outgoing call afterwards.
•
If resources are limited and your buffers for incoming and outgoing calls are limited
or full, you may wish to disregard the incoming call and continue with the outgoing
call to free up resources.
•
If you have a high-priority outgoing call, you may wish to disregard the incoming
call and go ahead with your transmission.
Troubleshooting
Table 1-5 provides a cross reference for pin and CCITT numbers for RS-232 circuits as
shown in Figure 1-6. Use this circuit information for monitoring or troubleshooting the
V.25 bis operation.
Table 1-5. V.25 bis Circuit Name Cross Reference
CCITT Mnemonic RS-232 Circuit
Pin
Number Bell Code
None None Protective ground 1 AA
102 SG Signal Ground (Common Return) 7 AB
103 SD Transmitted Data 2 BA
104 RD Received Data 3 BB
105 RTS Request to Send 4 CA
106 CTS Clear to Send 5 CB
107 DSR Data Set Ready 6 CC
108 DTR Data Terminal Ready 20 CD
109 CD Carry Detect 8 CF
114 ST Transmission Signal Element Timing
(DCE Source)
15 DB
115 RT Receiver Signal Element Timing
(DCE Source)
17 DD