TransCore MPRX, System Manual

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System Guide
TransCore Proprietary 8–14
Figure 8 – 9 MPRX RF Control Options
Presence Detector Controlling RF Transmission
The presence detector can be a loop detector, a track circuit, an infrared sensor, an
ultrasonic sensor, or another presence detection device that is connected to sense input0
to turn on the MPRX RF transmitter. In Figure 8-9, Option A shows a presence detector
controlling the RF transmitter. This operation is ensures that the RF is “on” only when a train
is in the MPRX read zone. Command #641 Select RF-by-Input Control (factory default) must
be enabled.
To set the option of the presence detector controlling the MPRX
• Ensure that the host device is in command mode.
• Enter command #641. Press ENTER.
• Leave the setting on RF-by-input control for normal operation.
Host Controlling RF Transmission
In Figure 8 – 9 , Option B shows the host controlling the RF transmitter. This is the most
common implementation.
If the presence detector is connected to the host device, as shown in Option B, commands
#6400 RF Off and #6401 RF On sent from the host device turn on and off the MPRX RF
transmitter.
Sense Inputs
The RS–232 configuration used by the MPRX has two sense inputs — SENSE0 and
SENSE1. SENSE0 is used to enable RF on antenna ports 0 and 1 if enabled, and SENSE1
is used to enable RF on antenna ports 2 and 3. The sense input circuits are used to notify
the MPRX of train presence and are designed to be connected to a free- of-voltage dry
contact. The MPRX sense inputs are designed to connect to a dry contact closure.