Black Box Series 5000 Reference Manual page 40

Link Interfaces Reference
RS530 Null-Modem Cable Configuration
DB25 MALE
1
Shield
2
Transmitted Data (A)
14
Transmitted Data (B)
3
Received Data (A)
16
Received Data (B)
4
Request To Send (A)
19
Request To Send (B)
5
Clear To Send (A)
13
Clear To Send (B)
6 DCE Ready (A)
22
DCE Ready (B)
20 DTE Ready (A)
23
DTE Ready (B)
7
Signal Ground
8 Received Line Signal Detector (A)
10
Received Line Signal Detector (B)
15
Transmit Timing (A) DCE Source
12
Transmit Timing (B) DCE Source
Transmit Timing (A) DTE Source
24
Transmit Timing (B) DTE Source
11
18
Local Loopback
21 Remote Loopback
Receiver Timing (A) DCE Source
17
Receiver Timing (B) DCE Source
9
25
Test Mode
The connecting cable must be a shielded cable.
Circuits which are paired (contain an (A) and (B) reference) should be connected to twisted pairs
within the connecting cable.
This cable is needed when it is necessary to connect two units back-to-back and a set of
modems is not available. Note that this cable specifies DB25 connectors on each end to allow
direct connection to the link interface connector on each unit.
The link speed must be defined for each of the two units.
Received Line Signal Detector (A)
Received Line Signal Detector (B)
Receiver Timing (A) DCE Source
Receiver Timing (B) DCE Source
Transmit Timing (A) DTE Source
Transmit Timing (B) DTE Source
Transmit Timing (A) DCE Source
Transmit Timing (B) DCE Source
Figure 3 – 13 RS530 Null-Modem Cable
40
DB25 MALE
1
Shield
Received Data (A)
3
Received Data (B)
16
Transmitted Data (A)
2
Transmitted Data (B)
14
DCE Ready (A) 6
DCE Ready (B)
22
Clear To Send (A)
5
Clear To Send (B)
13
Request To Send (A) 4
19
Request To Send (B)
8
10
7
Signal Ground
20
DTE Ready (A)
23
DTE Ready (B)
17
9
24
11
18
Local Loopback
21
Remote Loopback
15
12
25
Test Mode