User manual

78 Relay Multiplexer Command Reference Chapter 3
NOTE Channel numbers can be in the channel_list in any random order. Hovever,
opening order for multiple channels with a single command is not
guaranteed.
Opening the Control Relays: The control relays (0990 to 0996) can be
opened to perform special functions (for example, isolating channels
from the analog bus). Channels must be changed after the multiplexer
has been configured using the [ROUTe:]FUNCtion command. Open:
• 0990 to select the HI terminal for one-wire switching
• 0991 to connect Cable Test terminal to the one-wire LO COM terminal
• 0992 to disconnect lower 32 channels (banks 0 to 3) from the analog
bus
• 0993 to disconnect upper 32 channels (banks 4 to 7) from the analog
bus
• 0994 to disconnect lower and upper analog buses
• 0995 to disconnect lower and upper common buses (dual 32-channel
two-wire operation)
• 0996 to disconnect analog bus Guard from the LO line on the upper 
32 channels (banks 4 to 7)
*OPC? Command: Using the *OPC? command after the OPEN command
in your programs will ensure that the channel OPEN command has
executed prior to performing the next function (measure, read, etc.). This
programming practice is highly recommended.
Related Commands: ROUTe:]CLOSe, [ROUTe:]OPEN?, [ROUTe:]SCAN
*RST Condition: All multiplexer channels are open.
Example Opening Multiplexer Channels
This example opens channel 0, bank 0, in card #1 and channel 7, bank
6, in card #2 of a two-module switchbox. Both modules are in two-wire
mode.
OPEN (@100,267)
!100 opens channel 0, bank 0 of card #1
and 267 opens channel 7, bank 6 of

card #2