Owner manual

16
Channel properties are organized by tabs. The tabs that are relevant for a particular timing mode
appear automatically when that timing mode is selected. For convenience, all settings are retained
and saved, including those for timing modes that are not currently selected.
Four additional buttons appear next to the tabs:
- Disable temporarily disables the channel. The channel remains fixed in its “quiescent
state” (see Quiescent States below). The front panel LED for that channel will be unlit
(See Running Experiments: Channel LEDs).
- Enable restores channel functions following a temporary disable. The front panel LED
for that channel will glow to indicate the channel's status.
- Reset reinitializes the internal trigger counters and sweep timing for the current channel.
This function can be called simultaneously for all channels by pressing the Reset button
on the main tool bar.
- Force Trigger lets you simulate a valid input signal for the channel (see Channel
Properties: Logic for more). This button, which is only available with functions that can
be triggered, is useful both for troubleshooting your channel settings and implementing
software control of experiments. You can also force-trigger a channel from the Model
725 front panel (See Running Experiments: Force Trigger).
Quiescent States
When you disable a channel, its input will not change the output. The “quiescent state” of a
channel is the setting of its output when the channel is disabled. You can set each channel’s
quiescent state to be a TTL high (3.5–5 V) or low (0–0.2 V) to provide a safe signal to the output
device if you need to abort an experiment or stops its progress.
The method for setting the quiescent state depends on the timing mode. Most modes include an
Invert Output option which sets the output normally High.