41
This connection is an integral part of the interlock safety circuit. If a number of units are incorporated
in a system, then these connections can be “daisy-chained” together to form a single safety circuit. If
no external interlock circuit is required, then the shorting connection must be made by using the
terminator connector supplied. Otherwise pulse generation in the system will be inhibited.
A built in circuit breaker enables the EUT power supply also to be switched off, while the interlock
function only blocks the generation of pulses or any other ongoing test resp.
The interlock is a safety function to ensures the following:
The interlock forms a bus to which all instruments in a system are connected.
The interlock feature can be connected to external safety devices (door contacts, test
enclosure hoods, etc.).
If any part of the interlock circuit is interrupted, all the generator modules are inhibited from
producing or switching high voltages. Additionally, the power supply to the EUT can be
switched off too.
Activation of this safety feature is reported to the master controller.
The master controller is also notified when the interlock facility is reset.
Once the interruption is over and the re-instatement of the interlock has been acknowledged,
then power to the EUT is restored.
Activation of the interlock function is achieved without the help of microprocessors and software. This
ensures that the safety feature is not affected or hindered in the event of a program crash.
8.2 Trigger to scope output signal
Between Pin 18 (hi) and Pin 2, 8, 15, 20 (low)
Inactive state: at 24 V, in the active state: < 2.4 V
Note: The trigger signal has generally a duration of approx. 50 μs e.g. for surge testing.
8.3 Synchronization (Sync) signal: Output signal
Between pin 7 (hi) and pin 2, 8, 15, 20 (low)
Inactive state: at 24 V; in the active state: < 2.4 V
The sync signal consists of a level that goes low for each cycle of the mains frequency. The reference
is the signal at the power supply input (“EUT supply IN”). The position (timewise) of the sync signal
corresponds to the specified phase angle (converted into time, irrespective of the supply frequency).
The sync signal is only active while an AC test is in progress and Phase is set to
sync.
8.4 Pulse enable / next step input
Between pin 17 (hi) and pin 2, 8, 15, 20 (low)
Input open = inactive; input shorted = active
If this input is activated during a test run the test is halted (exactly the same as the pause function in
the control software). The test will continue to run as soon as the input is made inactive again.
If the input is already active before a test is implemented, then the test cannot start.