User manual

38 Using the Relay Multiplexer Chapter 2
Analog Bus Connection When Not Scanning. When opening and closing
individual channels in all four modes of operation, the analog bus can be
connected by switching the control relays (0992-0994, 0996) using the
OPEN and CLOSe commands. See [ROUTe:]OPEN and [ROUTe:]CLOSe
for additional information.
Relay Switch Card Configuration. In all modes of operation the relay switch
card wire jumpers can be changed to 1x8 or 1x16 configurations as required.
See “Configuring the Switch Card Wire Jumpers” for additional information.
Switching Channels
Examples
Four example programs follow that illustrate one-wire, two-wire, three-wire,
and four-wire modes of operation for switching multiplexer channels. The
examples are:
• Example: Switching Channels (One-Wire)
• Example: Switching Channels (Two-Wire)
• Example: Switching Channels (Three-Wire)
• Example: Switching Channels (Four-Wire)
Example: Switching
Channels (One-Wire)
This example illustrates one-wire mode operation. For the example, the HI
terminal is used. Bank 2 channel 1 is closed, connecting the HI terminal to
the one-wire HI COM terminal. Figure 2-1 shows how the multiplexer is
configured.
For one-wire operation, the control relays are set as follows. 0990 depends
on HI or LO terminal selection. 0991/0995 are set closed. 0992 will close
when SCAN:PORT ABUS is selected during a scan (see “Scanning
Channels”). 0993/0994/0996 remain in current state (open if not changed

after *RST)
To connect the HI terminals of bank 2 channel 1 to the one-wire HI COM
terminal, execute:
FUNC 1,WIRE1
!Configures the multiplexer (card 01) for
one-wire operation
CLOS (@10121)
!Connects the HI terminal of bank 2 channel

1 to the one-wire HI COM terminal
NOTE If the status register switch is set to one-wire operating mode, the FUNC
1,WIRE1 command is not required. When operating in the one-wire mode,
only one channel at a time can be closed.