Null-Modem Connections - GE ALPS Instruction Manual

8 LOCAL USER INTERFACE
A PC can be connected directly to the relay without a modem through a null-modem cable. The required pin-to-pin connec-
tions for the PC null-modem cable are shown below in Figure 8–4: 25-PIN NULL MODEM CABLE. The pin-to-pin connec-
tions for a null-modem cable to the 9-pin connector on the KEYPAD/DISPLAY INTERFACE are shown below in Figure 8–5:
NULL MODEM CABLE FOR PORT PL1. The null modem cable should be no more than 50 feet long.
T D 2
R D 3
R T S 4
C T S 5
D C D 8
D S R 6
RI 22
D T R 20
G N D 7
TO RELAY
PL-2 & 3
T D 2
R D 3
D S R 6
RI 9
D T R 4
R T S 7
C T S 8
D C D 1
G N D 5
TO RELAY
PL-1
Table 8–6: MODEM COMMANDS FOR COMMUNICATION BETWEEN RELAY AND PC
FUNCTION
DTR Status
Result Code Format
Result Code Display
Command State Echo
Auto-Answer
Carrier Detect
Jack Type
Command Recognition
Comm. Std. (@1200 bps)
Response to DTR
Fall Back to 4800Bd
Pulse Dial Ratio
GE Power Management
REMOTE COMMUNICATIONS PC DIRECTLY
NULL MODEM CABLE
Figure 8–4: 25-PIN NULL MODEM CABLE
REMOTE COMMUNICATIONS FROM PL-1 MODULE
NULL MODEM CABLE
Figure 8–5: NULL MODEM CABLE FOR PORT PL1
ALPS MODEM (REMOTE)
Follow DTR (&D3)
Numeric (V0)
Disable (Q1)
Disable (E0)
Enable (S0=1)
Follow CD (&C1)
RJ-11, etc. (&J0)
Disable (Dumb)
Bell 212A (B1)
Ignore DTR (&D0)
AT#F1
39%Mk/61%Bk (&P0)
ALPS Advanced Line Protection System
8.4 REMOTE COMMUNICATION INTERFACE

8.4.5 NULL-MODEM CONNECTIONS

2 T D
3 R D
4 R T S
5 C T S
8 D C D
6 D S R
22 RI
20 D T R
7 G N D
TO PC
2 T D
3 R D
6 D S R
9 RI
4 D T R
7 R T S
8 C T S
1 D C D
5 G N D
TO PC
PC MODEM (LOCAL)
Follow DTR (&D3)
Numeric (V0)
Disable (Q1)
Disable (E0)
Disable (S0=0)
Follow CD (&C1)
RJ-11, etc. (&J0)
Enable (Smart)
Bell 212A (B1)
Ignore DTR (&D0)
39%Mk/61%Bk (&P0)
8
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