TransCore 05531 User Manual

connected to a free-of-voltage dry contact. Sense output circuits are single-pole, dou-
ble-throw relays that provide normally closed and normally open dry contacts. The 
relay contacts are rated at 42.2V AC peak (30 Vrms) or 60V DC at 1 A maximum. If 
controlling an external gate or device requiring high current, an isolation transformer 
is required.

The following sections provide information to connect the sense input and sense out-
put circuits. 

The Encompass 4/4800 Multiprotocol Reader supports two sense inputs 

–

 sense 

input0 and sense input1

–

 which requires two sense input lines for each loop sense or a 

total of four sense input connections. Sense input0 is the presence detection device 
line and is used to control RF power. As shown in 

, sense input0 is through 

the red/green wire pair on the I/O pigtail. The Encompass 4/4800 Multiprotocol 
Reader expects the sense input0 circuit to close when a vehicle is present (i.e., a nor-
mally open condition). The minimum presence true period is fixed at 0 ms, which 
indicates that no delay occurs in closing the circuit when a vehicle is present.

Sense input1 allows the Encompass 4/4800 Multiprotocol Reader to monitor the status 
of a peripheral device. The host computer can then check the status by polling the 
Encompass 4/4800 Multiprotocol Reader.

The Encompass 4/4800 Multiprotocol Reader supports three sets of sense output sig-
nals. Two sets

–

 sense output0 and sense output1 

–

 provide normally open or normally 

closed sense outputs. The third sense output set is dedicated for testing and set up of