User manual

Stepping and scanning trigger model additions

The trigger model presented in “Trigger operations” earlier in this section has some addi-

tional capabilities when stepping or scanning. These are outlined below:

• Timer — With this control source, event detection is immediately satisfied on the ini-

tial pass. Each subsequent detection is satisfied when the programmed timer interval

(up to 99H:99M:99.99S) elapses.

• Reading counter — For both stepping and scanning, the reading count can be en-

tered from SHIFT-CONFIG. (This is referred to as the trigger counter over the bus.)

The reading counter can bypass the idle state. Operation will wait until the pro-

grammed control source event occurs.

• Channel counter — For scanning, the scan list length (maximum channel less mini-

mum channel) is used to bypass the control source allowing a specified number of

device actions to occur. (This counter is referred to as the sample counter over the

bus.)

These additional blocks are shown in the trigger models of Figures 3-12 and 3-13. Uses

of the timer control source, reading counter, and channel counter are shown in the scanning

examples later in this section.

Idle

Control

Source

Immediate

External

Timer

Event

Detection

Delay

Device

Action

Output

Trigger

Readings

Reading

Count

(Trigger counter)

Yes

Figure 3-12

Front panel trig-

gering with step-

ping

2000-900 (J - Aug 2010) BOOK.fm Page 24 Wednesday, October 12, 2011 12:29 PM