Installation and Commissioning
GARD 8000 SYS RFL Electronics
November 28, 2017 4-48 973.334.3100
5. Adjust the Gain pot (R8) on the Power Amplifier until the nominal TX level is shown on the
FSVM.
6. Confirm TX Fail Output is Off.
4.6.3.2 HYBRID TUNING PROCEDURE
If this is a 2W system, perform the following Hybrid Tuning Procedure. The purpose of tuning the
hybrid is to match the impedance of the GARD 8000 PLC system to the transmission line, thereby
minimizing reflected power. Refer to Figure 4-16.
a. On the Analog Module, verify that jumper locations J12 through J15 do not have jumpers
installed.
b. Using the FSVM, set to transmit frequency, monitor the RX IN Test Point (Yellow) and
(Ground black), on the Analog Module.
c. On the Analog Module verify that J24 is in the FSK position. Adjust S1 (Course) and R46
(Fine) for a minimum reading on the FSVM.
d. Insert jumpers J12 through J15 in increasing combinations of capacitance until a combination
of capacitance is found to give a minimum reading on the FSVM. Refer to the schematic shown
in Figure 10-34.
e. Remove jumper J17 and adjust L4 for fine tuning until a minimum reading on the FSVM is
achieved. If necessary remove jumpers J16, J18, J19 and J20 in increasing combinations of
inductance until a combination of inductance is found to give a minimum reading on the
FSVM. Refer to the schematic shown in Figure 10-34.
4.6.3.3 SETTING THE RX LEVEL
a. Both the Local and Remote units should be tied to the line at this time.
b. From the remote end, Guard should be received (in 2F or 3F systems), or actively send a
Block (in On/Off systems).
c. Verify that both PLC GARD units have no active alarms. Observe the PLC Status Web Page,
the general GARD Home Page, and form-C relay Major and Minor contacts on the GARD
Power Supply I/O.
d. In the PLC Test Page, select the “Re-Commission” box and click “Run Test” for each unit.
The Tx level should now be reported in the web pages as 0dB. This receive level will now be
used as a nominal reference. Acceptable receive range from the line [5mV ----25Vrms].
Refer to the dBm chart for the correct terminal impedance. An adequate Rx level would be
1W-30dBm @ 50-ohms.
NOTE
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