Servicing Information

91

RS530 / RS422 Null-Modem Cable
Shield
TransmittedData(A)
TransmittedData(B)
ReceivedData(A)
ReceivedData(B)
RequestToSend (A)
RequestToSend (B)
ClearToSend (A)
ClearToSend (B)
DCEReady(A)
DCEReady(B)
DTEReady(A)
DTEReady(B)
SignalGround
ReceivedLineSignalDetector(A)
ReceivedLineSignalDetector(B)
TransmitTiming(A)DCE So urce
TransmitTiming(B)DCE Source
ReceiverTiming(A)DCE Source
ReceiverTiming(B)DCE Source
LocalLoopback
RemoteLoopback
TransmitTiming(A)DTE Source
TransmitTiming(B)DTE Source
TestMode
ClearToSend (A)
D
B
2
5
M
A
L
E
1
2
14
3
16
4
19
5
13
6
22
20
23
7
8
10
15
12
17
9
18
21
24
11
25
D
B
2
5
M
A
L
E
1
3
16
2
14
6
22
5
13
4
19
8
10
7
20
23
24
11
17
9
18
21
15
12
25
TransmittedData(A)
ReceivedData(A)
TransmittedData(B)
ReceivedData(B)
DCEReady(A)
DCEReady(B)
ClearToSend (B)
RequestToSend (A)
RequestToSend (B)
ReceivedLineSignalDetector(A)
ReceivedLineSignalDetector(B)
DTEReady(A)
DTEReady(B)
SignalGround
TransmitTiming(A)DTE Source
TransmitTiming(B)DTE Source
LocalLoopback
RemoteLoopback
ReceiverTiming(A)DCE Source
TransmitTiming(A)DCE Source
TransmitTiming(B)DCE Source
TestMode
Shield
ReceiverTiming(B)DCE Source

Figure C-13 RS530 / RS422 Null-Modem Cable

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.