Series 3700A System Switch/Multimeter Reference Manual
Section 5: Switching and scanning
3700AS-901-01 Rev. D/June 2018
5-15
You incur settling times at each close or open operation. If sequential connection is not selected,
action settling times may vary depending on the card type. The total settling time is the sum of the
settling times for each specified channel, plus any user delays that have been set for any closed
channels. To better calculate timing, you can enable sequential channel connections. Deterministic
implies that you can determine the time for a close operation to happen. For example, if you close
three channels and each takes 4 ms to close, with sequential on, it will take 12 ms. With sequential
off, it may be 4, 8 or 12 ms, depending on whether or not the card can close multiple channels at
once.
Opening and closing relays in a sequential manner also uses minimum power. Since only one relay is
closed or opened at any given time, the power used for that action is for a single relay and not
additive.
By default, sequential connections are turned off. The order in which channels are opened or closed
is not guaranteed. This feature also applies to scanning.
The sequential setting affects all channels in the instrument.
When specifying multiple channels for a single close or open operation, the total settling time
depends on the relay drive scheme for the switching module
— how each switching module budgets
power to change the state of its relays. The Series 3700A supports the following relay drive schemes:
•
Direct Drive: You can simultaneously update the state of all relays on a switching module with a
single close or open operation. The total settling time for a close or open operation is the settling
time for a single relay.
•
Matrix Drive: You can execute a close or open operation on a list of channels, which can result in
multiple actions to update the state of all specified relays. Settling time varies depending on the
capabilities of the card and the number of relay closures.
•
Hybrid Matrix Drive: For a single close or open operation, the state of all relays can be updated in
no more than two steps. The total settling time for a close or open operation does is less than
twice the settling time for a single relay.
To enable sequential connections through the front panel interface:
1. Press the
MENU
key.
2. Use the navigation wheel to scroll to the CHANNEL menu item.
3. Press the
ENTER
key.
4. Select the
SEQUENTIAL
menu item.
5. Select
ON
or
OFF
.
6. Use the
ENTER
key to apply the selection.
7. Use the
EXIT (LOCAL)
key to leave the menu.
To enable sequential connections through the web interface:
1. Open the
UNIT
page.
2. In the upper left corner, select the Sequential check box (next to the Channel Connect Rule list).
To enable sequential connections through the remote command interface:
Send the command:
channel.connectsequential
