Cypress CTM-130 manual Mounting and attaching the GPS antenna, Connecting to the I/O Port

7.5 Mounting and attaching the GPS antenna

The GPS antenna used with the CTM-132 must be an active type with gain of at least 26dB and compatible with a 3.3 volt dc supply provided directly by the modem over the coax cable. The antenna installation should typically be on an upper horizontal surface of a vehicle with a clear 360 degree view of the sky.

The GPS antenna connector is a standard MCX type that requires the GPS antenna cable to use a MCX plug connector. The CTM-132 can be provided with alternate antenna connector types – contact Cypress Solutions for details.

7.6 Connecting to the I/O Port

The I/O port provides for the control of 4 external devices and for monitoring 6 external sensors. Connections are made via the 14 position connector.

Output Connection

The 4 outputs are configured as “open drain” which means that they can be directly connected to energize external relays, lamps or other DC devices. Maximum supply voltage is 36 volts, with a maximum load current of 500mA. Maximum wire gauge for use with the connector is 16AWG. Connections can be made as shown:

Note that the DGND connection is referenced to the modem’s supply ground.

Input Connection

The 6 inputs may be configured in the modem for monitoring a digital DC voltage state or an analog DC voltage.

For digital state monitoring the minimum input voltage is 0 volts while the maximum is 36 volts. The threshold detection voltage is 2.5 volts with 1 volt of hysterisis. Connections can be made as shown:

© 2007 Cypress Solutions Installation and Operation Manual: CTM-130 / CTM-132 (Revision 1.2) Page - 15 -