Icm Functions - Motorola VRS750 Service Manual

ICM Functions

The in-car-monitor (ICM) allows limited use of the mobile while the
VRS is enabled.
<ICM Base> Mode
In this mode pressing the mobile's PTT will cause the mobile to
transmit on the mode shown on the control head display. The VRS will
not transmit the mic audio to the portable. During portable-to-base
repeat operations pressing the mobile's PTT will result in the talk
prohibit tone sounding momentarily and the mic audio will not be
transmitted to the portable. When the mic is on HUB portable
transmissions will not be heard at the mobile's speaker. When the mic
is off HUB only portable transmissions with the proper PL will unmute
the speaker. The following paragraphs detail how the VRS should
operate in <ICM Base> mode during different cases.
1. No VRS repeat operations in progress and the mobile user initiates
a PTT.
• The mobile will key up and transmit mic audio to the base.
• Mic-Hi line audio is not routed to the VRS transmitter.
2. During a portable-to-base repeat operation, the mobile user
initiates a mic PTT.
• A momentary talk prohibit tone will be heard and the mic
audio will be disabled.
3. During a base-to-portable repeat operation, the mobile user
initiates a mic PTT.
• The base-to-portable repeat operation will be interrupted.
• Mic-Hi line audio is not routed to the VRS transmitter.
• The mobile will key up and transmit mic audio to the base.
• When the mobile mic PTT is released, the base-to-portable
repeat will continue if the mobile is still receiving a base
transmission.
<ICM Both> Mode
In this mode pressing the mobile's PTT will cause the mobile to
transmit on the mode shown on the control head display and cause
the VRS to transmit to the portable. If the portable is using a PL
frequency then the VRS can be programmed to transmit the proper PL.
During portable-to-base repeat operations pressing the mobile's PTT
will result in the talk prohibit tone sounding momentarily and the mic
audio will not be transmitted to the portable. When the mic is off HUB
all portable transmissions are heard at the mobile's speaker. When the
mic is on HUB only portable transmissions with the proper PL will
unmute the speaker. The following paragraphs detail how the VRS
should operate in <ICM Both> mode during different cases.
1. No VRS repeat operations in progress and the mobile user initiates
a PTT.
• Mic-Hi line audio is routed to the VRS and transmitted to the
portable.
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