2-2
Functional Description
The eight electro-mechanical relay outputs (contact closures) are
addressed as a single I/O byte. Five of these relays are Form C (SPDT)
contacts, and three of the relays are Form A (SPST and normally open).
The relay contacts are silver alloy and are rated at 3A at 125VAC or
28VDC with a resistive load. The state of the relays can be determined by
reading back the data from the same I/O port.
The eight individual, optically isolated inputs can be read as a single I/O
port byte. Inputs are not polarity-sensitive and can be driven from DC or
AC (50 to 1000Hz) control voltages in the range of 5 to 24V
rms
. Each
input includes a switchable, slow/fast filter with a time constant of 5ms.
For AC input voltages, you must switch in the filter. For DC input
voltages, you can switch out the filter to obtain response speeds of less
than 50µs, or you can switch in the filter for maximum noise suppression
or contact debouncing. You can also mix inputs of AC and DC voltages,
and you can drive inputs from standard 12/24VAC control transformers.