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User Manual 1260-38
2 Addendum Page 6/98
Control Information for the 1260-38A and 1260-38B
The following information describes the control-register-to-relay-channel mapping for a 1260-38A or 1260-38B
Relay Module. This information may be used to control the module when using a 1260-01T in the register-
based mode of operation.
Each channel on this module is controlled by setting or clearing a single bit. Control Registers on the module
operate 8 channels simultaneously. There are eight control bits per Control Register. Setting the bit to a 1
closes the relay; setting the bit to a 0 opens the relay.
The table below shows the mapping between logical channels used to operate the relay module in message-
based mode and the bits within the Control Registers that may be used to operate the channel in register-
based mode.
Each Control Register is located 2 addresses from the previous Control Register. This is shown in Table 2-2
of the 1260-01T manual. Control Register 0 is located at the “Base A24 Address” for the module. Consult the
“Register-Based Operation” Section of Chapter 2 of the 1260-01T manual for a description of calculating
control register addresses.
Note that when the 1260-01T message-based interface is used, ODD MUXes (channels 10 through 17, 30
through 37, channels 50 through 57, …, 150 through 157) are operated in parallel with EVEN MUXes to
operate as a 4-wire MUX. That is, when channel 0 is closed using the message-based interface with a 1260-
38B, the firmware also closes channel 10; when channel 143 is opened, the firmware opens channel 153 as
well.
Channel
Control Register
Control Bit
0
0
0
1
0
1
2
0
2
3
0
3
4
0
4
5
0
5
6
0
6
7
0
7
10*
1
0
11*
1
1
12*
1
2
13*
1
3
14*
1
4
15*
1
5
16*
1
6
17*
1
7
20
2
0
21
2
1
22
2
2
23
2
3
24
2
4
25
2
5
26
2
6
27
2
7
30*
3
0
31*
3
1
32*
3
2
33*
3
3
34*
3
4
35*
3
5
36*
3
6
37*
3
7
40
4
0
41
4
1
42
4
2
43
4
3
44
4
4
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