Varec 4000 - Manual (Page 54)

ATT Family of Products Tank Gauge Transmitter
44 Installation and Operations Manual
8.2 Model 4050 Digital Input/Output Unit
The Model 4050 is a digital I/O unit. It includes four digital contact closure outputs and four digital inputs. It operates
connected to and is powered from the ATTI bus. The unit is mounted in a round explosion proof junction box. Three
3/4-inch conduit entries are available.
•
Primarily configured by jumpers. Three sets of jumpers are used.
•
Unit address: 4 jumpers for range 0-15. Digital I/O units normally use address 4,5 or 6.
•
Active state jumper for each digital output. Jumper determines if contact is N. O. or N. C.
•
Default power condition for each digital output. Jumper determines if contact is open or closed when no power is
applied.
8.2.1 Digital Outputs
The use of the digital outputs is configured within the ATT using the handheld interface. Digital outputs 1 - 4 can be
configured as follows:
1. Set output as level switch:
•
Set for low or high closure.
•
Set level to actuate.
2. Set output for Modbus command to write.
8.2.2 Digital Inputs
Digital inputs 1 - 4, can each be read with a Modbus command.
8.2.3 Relay Specifications
The latching relays will switch 110 VAC at 1 A or 24 VDC at 2 A. The unit does not support 220/230 VAC.