ZETRON Model 25, Product Manual, Page: 35 / 147

Operation
025-9567E 27
Direct Keying
1. Is PTT still closed and are the currently closed control relays same as the desired
control relays?
:Yes - Skip remaining steps here
2. Open PTT relay
Open control relays
Wait 150 milliseconds

SAMPLE CHANNEL BUSY
3. Is channel busy used and has it been busy for over 30 seconds?
:Yes - Skip remaining steps here
4. Close programmed control relays
Wait 150 milliseconds
Close PTT relay (if verify mode off)
Wait the programmed key-up delay
Close the audio relay
Sample Channel Busy
1. Is channel busy used?
:No - Skip remaining steps here
2. Is channel busy?
:No - Skip remaining steps here
3. Print “BUSY”
4. Issue a beep
Display “bUSY” momentarily
5. Is a key pressed?
:Yes - Skip remaining steps here
6. Is the 30 second time-out over?
:No - Go back to step 4.
7. Print “BUSY OUT”
Do not proceed with key-up for this call