The CABLE PAYOUT Monitor (CPM) (Figure 1-12-9) is installed on the sonar operators console. It consists of a small lightweight digital voltmeter which provides the sonar operator with a continuous indication of the length on sonar cable paid out.

The CPM operates on 115 VAC, 400 Hz and is protected by a circuit-breaker marked “CPM II” located on the co-pilots AC circuit-breaker anel.

Serviceability of the CPM is ascertained by depressing the TEST button on the face of the panel. The resulting digital readout of 500 +15 indicates a serviceable CPM.