Specifications

Table Of Contents
OPERATIONS
Page 52 MRC-565 Packet Data Radio Operations & Maintenance
timeout the time limits may be set by entering the number of seconds, from 0 to 32767. Enter a 0
to turn off the time limit.
Command Description
STT,secs The Set Teleprinter Timeout command sets the time limit for characters at the
maintenance terminal. Default is 60 seconds (1 minute).
5.3.4 Defining Data Relays
The ambient noise conditions at a remote station site may sometimes be excessive and a poor
communication path to the Master Station will result particularly if the remote station is
operating in a meteor burst mode. To overcome this problem, another MRC-565 may be placed
in a nearby quiet location and used as relay station between the MRC-565 at the noisy site and its
master station. When used as a relay, the MRC-565 will concentrate the data reports it receives
from one or more neighboring remote sites and forwards the data to the Master Station.
In this mode, the MRC-565 must be defined as a Master Station. The relay will then receive
Group data reports from other MRC-565 units located in noisy or un secure locations and
repackage them and forward them to the Master Station. A relay can handle sixteen GROUP
reports. These reports can be in any combination; i.e., four groups from each of four Remote
units, one group from each of sixteen Remote units or any combination in between. Substitution
tables must be established in both the relay unit and at the Master Station to manage the relay
function.
When a designated GROUP report is received at the relay, it will substitute its own ID and group
number in the report as defined in its substitution table and forward the data to an MRC-520B
Master Station using the MRC-550C RF format rather than the standard MRC-565 message
format. When the relayed data is received at the MRC-520B it reconstructs the original data
report based on its own substitution table and route the report as required.
The following command is used to define the entries in the substitution table for a relay unit:
SUBST,relay_id,relay_group,remote_id,remote_group
where: relay_id is the relay unit's ID
relay_group is the data group report number at the relay
remote_id is the originating Remote unit's ID
remote_group is the data group report number at the originating Remote unit
5.3.5 Scaling A/D Readings
The MRC-565 contain a 12 bit A/D converter that is used to measure 16 analog voltages input
including: