User's Manual

MDS 05-3447A01, Rev. F MDS 1710A/C and MDS 2710A/C/D 37
The RTU simulator shown in the test setup (MDS Part No. 03-2512A01)
is a microcontroller that emulates a remote terminal unit operating at
1200, 2400, 4800, or 9600 bps. Custom software is supplied with the
RTU simulator that allows continuous polling of remote radios using an
IBM-compatible personal computer. The software reports the number of
polls sent, polls received, and the number of errors detected.
As an alternative to using an external RTU simulator, the transceiver’s
internal RTU simulator may be used (see
RTU command in
Table 7 on
page 20). (This will not provide as conclusive a test as an external sim-
ulator because it does not utilize the transceiver’s data connector.)
NOTE: It is very important to use attenuation between all units in the
test setup. The amount of attenuation required will depend on
the number of units being tested and the desired signal strength
(RSSI) at each transceiver during the test. In no case should a
signal greater than –50 dBm be applied to any transceiver in
the test setup.
Invisible place holder
Figure 14. Typical setup for bench testing of radios
7.4 Helical Filter Adjustment
If the operating frequency of the radio is changed significantly, the
helical filters should be adjusted for maximum received signal strength
(RSSI). To adjust the filters, proceed as follows:
1. Remove the top cover from the transceiver by loosening the four
screws and lifting straight up.
2. Locate the helical filters on the PC board. See
Figure 15.
ANTENNA
13.8
VDC
+
–
ANTENNA
13.8
VDC
+
–
ANTENNA
13.8
VDC
+
–
ANTENNA
13.8
VDC
+
–
POWER ATTENUATORS
• Fixed or adjustable
• 5W Minimum Rating
POWER DIVIDER
NON-RADIATING ATTENUATOR
• Install on any unused divider ports
• 5W Minimum Rating
COMPUTER RUNNING MDS
"POLL.EXE" PROGRAM
RTU SIMULATORS
MDS P/N 03-2512A01*
MASTER STATION
REMOTE
REMOTE
REMOTE
REMOTE
* Transceiver's internal RTU Simulator may be used if
external simulator is unavailable. See text.