Serially Programmable Dry Contact/Dual State Voltage Interface Unit
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Description
This manual covers both the serially programmable Dry Contact interface unit and the serially programmable Dual State
Voltage interface unit. These products are designed to work with systems outputting either a dry contact closure, i.e. relay
output or a voltage from 5 Volts to 60 Volts DC. AC may be applied if the correct opto-isolators have been installed.
The serially programmable Dual State Voltage (
VSPDS
) unit consists of 128 opto-isolated inputs that will accept voltages
from +5 Volts dc to +60 Volts dc. The inputs can be configured as NORMALLY OPEN or NORMALLY CLOSED for
both the Dry Contact and the Dual State Voltage unit.
Each column of 8 inputs has a single “common” connector in the center of the group of terminals. The pager messages
are held in a non-volatile memory (EEPROM) which can be programmed by using the Microsoft Windows
Visual Basic
program , Dry Contact Voltage Interface Program (
DCVIP
).
The Serially Programmable interface board is housed in a 13”H x 7.5”W x 2.5”D wall mounted housing. Cable access is
via four inputs fitted with strain relief couplings. The unit requires 12 vdc, which is supplied by a 115-volt AC wall
adapter.
Because the need to analyze the conditions present on the inputs, the time between a condition being present, and the
message being sent is approximately 2 seconds. The scanning procedure does not cease when an input changes, i.e. the
system does not stop to analyze a single input, but scans all inputs a number of times (approx. 20ms for one scan) in the
two second scanning period. Any pending messages continue to be sent during the scanning period, in this way the
system operates continuously under all circumstances.