User guide

CCU Hardware Reference Theory of Operation
CTI Products, Inc.
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3.6 Section 5 – TX Normal / ECS Select
The Tx Normal / ECS Select section has a similar Toggle function as the
Main/Standby function.
There are three external inputs:
• /Tx Toggle 1 (from Console 1)
• /Tx Toggle 2 (from Console 2)
• /Tx Toggle 3 (from Console 3)
There are four logic outputs:
• /Tx Normal Select 1 (Normal)
• /Tx Normal Select 2 (Normal)
• /Tx ECS Select 1 (Inverted) To TX ECS Select Relay
• /Tx ECS Select 2 (Inverted) To Console Input
The TX ECS select can be used to disable the comparator repeat function. See
details in Section 2 - Repeater Control.
3.6.1 Slaved TX Select
The TX Normal / ECS Select section can be forced to be controlled by Section 4 -
Rx Normal / ECS Select as shown below:
Option
Switch Up Down
1 Slave Mode:
TX Normal / ECS Select
controlled by the
Rx Normal / ECS Section
Independent Mode:
TX Normal / ECS Select
operates independently from the
Rx Normal / ECS Section
Table 3 – Slaved TX Select
If the Slaved mode is used, the Toggle inputs to the TX section are not connected.
3.7 Section 6 – TSAM Force Select Output
When one of the Toggle sections (typically the TX Main/Standby) is used to
control the TX Select (TXS1 & TXS2) inputs on the TSAM Transmitter Steering
Unit, the TSAM requires an additional Force Select input. Section 6 provides a
square wave output with a period of about 1 Hz. This ensures that the TSAM's
outputs will switch within 1 second of the output change in the CCU.
The Force Select output is not fed back to the MCNRCD network, since it would
only add a lot of unnecessary channel traffic.