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1256E User Manual
SCPI Command Basics 5-38
Racal Instruments
©
2002
Closing Relays
The CLOSE command may be used to close channels. To say a
channel is closed, it means either:
a. The input of the channel is connected to the output (Single-
Pole Single Throw).
b. The input of the channel is disconnected from the “normally
closed” output and connected to the “normally open” output
(Single-Pole Double-Throw).
c. The common input of a mux is connected to the output
denoted by the channel number.
The syntax for the CLOSE command is:
[:ROUTe]
:CLOSe
<channel
list>
The format for a “<channel list>” is described in the previous
paragraphs of this section of the manual.
The CLOSE? command may be used to query the present state of
the relays in the system. This command returns a reply of a
sequence of “0" and “1", each of which are separated by a single
ASCII space character. The value of the reply is “0" if the
corresponding relay is opened, or “1" if the corresponding relay is
closed.
The reply is one-for-one with the <channel-list>. For example,
assume channels for a particular relay module at module address
7 are numbered as follows:
0, 1, 2, 3, 4, 10, 11, 12, 13, 14, 20, 21,
22, 23, 24, 30, 31, 32, 33, 34
This example module consists of 20 channels. Suppose that only
the following channels are closed, while the remainder are open:
3, 20, 31
The following examples show the replies to the “CLOSE?” queries.
Command:
CLOSE?
(@7(0:34))
Reply: