AT SERIES USER PORT OPERATION
Relay Drive Output Operation
Both the Voltech AT3600 and ATi transformer tester
possess a user port connector (9-way, 'D' type, female).
This connector has been designed to facilitate an
open-collector relay drive output.
The relay drive output is provided in a unique test
called "OUT". Six relay drive outputs are available to the user and can be
pre-programmed via the Voltech AT Editor software to output to a number of
sources or applications. Figure 1 below shows the pin-outs available for
the six relay drives:
|| O/P user relay drive 0
|| O/P user relay drive 2
|| O/P user relay drive 4
|| +12V DC @ 1A
|| O/P user relay drive 1
|| O/P user relay drive 3
|| O/P user relay drive 5
Each relay output can drive a load of >150Ω and has a
maximum current output of 80mA.
An "OFF" state for the relay drive outputs is the default
setting when the AT is switched on.
However, after each programmed "OUT" test, the relay
drives will remain in the programmed condition until another "OUT" test is
run, or the AT is switched off and on again.
During subsequent "OUT" tests, the AT, firstly,
identifies relays that are programmed to be "OFF" and releases those
Secondly, the AT identifies relays that are programmed to
be "ON" and energizes those next.
The relay switching "OFF" time is almost instantaneous.
Switching "ON" times, however, are around 20mS.