Meteor Communications Corporation MCC-545C, Эксплуатация и обслуживание, Страница: 47 / 88

OPERATIONS 4-11
MCC-545C PACKET DATA RADIO
12/2000
4.2.10 Scaling A/D Readings
The MCC-545C automatically scales the readings from its A/D converter for operator use. The
readings that require scaling are battery level, detected RF and transmit power. The scaling
factors that are required for these readings will depend on the type of hardware used at the MCC-
545C site and are set by operator command using the SCALE command. The SCALE
commands are summarized in Table 4.1.
There are four values that need to be scaled depending on the equipment configuration at the site:
!
Battery Voltage (used by the STAT/TEST commands)
!
Detected RF in db (used by the MM command, meteor monitor and BINS command)
!
Detected RF in microvolts (used by the STAT/TEST commands)
!
Transmit power level (used by the STAT/TEST commands)
The required scaling factors are determined by the power supply used in the packet data radio.
The RXTYPE command translates the receiver calibration curves from detected RF (in db) to
microvolts. These are nonlinear and significantly different for the MCC-527 and MCC-543
receivers..
To apply the scaling factors, the TXPWR A/D value must first be squared and then multiplied by
the scaling factor in the table. For the other values, use the A/D reading directly and multiply by
the appropriate scaling factor.
MCC-545C SCALING FACTORS
PARAMETER 12V 36V 28V
BAT
0.0623 0.05 0.1749
DETRF 0.0188 0.1074 0.0188
TXPWR
0.000353 0.00116 0.000353
RXTYPE
527 543 527
TABLE 4.1
4.3 Sending and Receiving Messages
The MCC-545C is a packet data radio and therefore enables an operator to send and receive
messages to all nodes within the network.
The messages may be entered from an operator terminal that is connected to the OPERATOR
PORT of the MCC-545C. There are three basic message types: (1) free-form text messages, (2)
canned messages and (3) commands. The general format for all messages is shown below:
MESSAGE, R , dest 1, dest 2, …dest n
where: R = Message priority; A is highest, Z is lowest.
dest = ID of the station(s) to which the message will be sent.