User manual

Series 3700 System Switch/Multimeter Reference Manual Section 13: Instrument Control Library (ICL)
3700S-901-01 Rev. C / July 2008 13-39
channel.close()
Example
To close Channels 1 to 5 on Slot 1, Channel 3 on Slot 3, and mychans:
channel.close('1001:1005, 3003, mychans')
To close Channel 1 on Slot 2 and analog backplane relay 3 in Bank 1 on Slot 2:
channel.close('2001, 2913')
channel.connectrule
Attribute
Indicates the connection rule for closing and opening channels in the system.
Usage
To read the connect rule:
rule = channel.connectrule
To write the connect rule:
channel.connectrule = rule
Set rule to:
channel.BREAK_BEFORE_MAKE or 1
to have BBM connections for relays in system
channel.MAKE_BEFORE_BREAK or 2
to have MBB connections for relays in system
channel.OFF or 0
to not guarantee a connection rule. The system will close relays as it is able to without
adhering to a rule.
Remarks
The connection rule describes the order in which switch channels are opened and
closed when using channel.exclusiveclose() (on page 13-41),
channel.exclusiveslotclose() (on page 13-43), dmm.close() (on page
13-123), and scanning commands like scan.execute() (on page 13-236) and
scan.background() (on page 13-232). These commands may both open and
close switch channels in a single command. The connection rule dictates the algorithm
used by the instrument to order the opening and closing of switches.
When the connection rule is set to channel.BREAK_BEFORE_MAKE, the
instrument ensures that all switch channels open before any switch channels close.
This behavior covers the most common applications and is considered the safest
connection rule because the tested device is completely decoupled from the
instrument. This is the default behavior. When switch channels are both opened and
closed, this command executes not less then the addition of both the open and close
settle times of the indicated switch channels.
When the connection rule is set to channel.MAKE_BEFORE_BREAK, the
instrument ensures that all switch channels close before any switch channels open.
This behavior should be applied with caution because it will connect two test devices
together for the duration of the switch close settle time. When switch channels are
both opened and closed, the command executes not less then the addition of both the
open and close settle times of the indicated switch channels.