Motorola MOSCAD 68P02958C00-B User Manual page 368

7. Transmits a constant tone during this period (in msec), before data transmission starts.
8. The maximum time frame (in seconds) for data transmission. Transmission over this time will be
terminated, and a failure will be declared. The transmission always ends (normally or forced) with a
constant tone for holdup time.
9. During this period (in msec), the system allows the plug-in modem to transmit the contents of its
internal buffer, after the MOSCAD RTU has finished data transmission. It is not recommended to
change this parameter.
10. The amount of time (in msec) a constant tone transmission is continued after the end of transmission.
11. The minimum waiting time (in msec) between one frame transmission and the next. It is measured
from the end of the constant tone of the last transmission.
12. Period (in msec) during which the trunk channel was quiet (RxEn but no tone),
13. Period (in msec) during which a transmission took place in trunk (both tone and RxEn).
14. Period (msec) during which a trunk channel was not available (no RxEn).
15. Whether the CPU is pressing TxEn now.
16. Whether PTT is pressed now and TxEn requested.
17. If TxEn is requested: The time (in msec) remaining for re-pressing/releasing the PTT. If TxEn was
not requested, the value is 0.
The access to trunk channel:
In order to begin transmission, the user should request TxEn from central unit. This is done by
pressing PTT for 4 msec. and releasing it for 5 msec. If someone else is transmitting, this request
interrupts the transmission, and therefore should be avoided.
Access to channel is available in low priority and then the waiting time is 1 msec during which there
is no channel (RxEn is not active and no one is transmitting) until requesting TxEn (for transmitting).
If during this time someone receives permission to transmit, RxEn will become active and again the
user should wait for it to become inactive.
Access to channel is also available in high priority and then the waiting time is either 2 msec, as
before, during which RxEn is not active until requesting TxEn, or 3 msec during which RxEn is active
and the channel is quiet (there is no Tone) before requesting TxEn.
C-76
Software Diagnostics Output