8.2.8 User Port
The User Port is positioned on the top moulding of the AT Series Testers, at the rear behind the fixture board recess.
The port contains six open-collector relay drive outputs, and two HC MOS compatible inputs.
The relay drives are switched on and off by certain optional tests (e.g. the OUT test) inserted into your test program. This will enable you, for example, to switch a dummy load on to the secondary winding of the transformer under test, so that subsequent tests are performed on the loaded transformer.
BEWARE OF HIGH VOLTAGES
Remember when designing relays into your fixture that the AT3600 is capable of producing very high voltages.
It is the responsibility of the user to ensure that both the relays themselves, and the associated wiring are able to withstand any high voltage produced in the test program.
It is particularly important that YOU ensure that there is never a flash-over from a high voltage test signal to a relay coil driven from the User Port. Such a flash-over would cause extensive damage to the circuits inside the Tester.
If in any doubt, contact your Voltech supplier for advice on which relay to use in your application.
9-pin female D-type connector.
USER RELAY DRIVE OUTPUTS (PINS 1, 2, 3, 6, 7 AND 8)
All the User Relay Drive Outputs have the following equivalent circuit
Relay coil resistance: > 150Ω
Maximum output current: 80mA per output
USER INPUTS (PINS 4 AND 9)
The User Inputs have the following equivalent circuit:
Maximum input voltage: +5V
Minimum input voltage: 0V
Minimum logic 1 input: 4V
Maximum logic 0 input: 0.25V
The zero reference voltage for these inputs is the 0V(ground) 4mm socket situated to the left of the User Port.