Table of Contents
Advertisement
1.
Connect a RF Signal Monitor to the transmit (TX) output, located on the rear panel of the SC720/SC820.
•
Set the input of the RF signal Monitor to the SC720/SC820 radio transmitter frequency.
Note:
2.
Move the shorting plug from pin group #7, on the DK1000 JP1 header, to pin group #7 on the DK1000 JP1
header to pin group #6 on the DK1000 JP1 header. The MODE LED will continue a BLINKING RED
illumination and the TX LED on the front panel will illuminate RED.
The SC720/SC820 is NOW transmitting a continuous data pattern.
3.
Set continuous test data level deviation to +1.5 KHz by adjusting the Modulation pot (MOD - R35), on the
DK1000 controller board; ±3.0 KHz for certain export models.
4.
Remove the shorting plug from pin group #6 on the DK1000 JP1 header.
5.3.3
Setting the Hanging Time
Hang Time is the amount of time that the transmitter will remain on after loss of the receive signal. The Hang
Time is set by Bosch, at the factory, so that the transmitter won't dropout between a poll and acknowledge (ACK)
message from the SC9000 Receiver and a Remote communications panel to shorten the total message transmit
time.
1.
Preset the Hang pot (HANG – R11) on the DK1000 controller board to the center of its rotation range.
2.
Initiate transmit (TX) with the SAFECOM lT500 Installation Tool. If an IT1500 is NOT available, SAFECOM
communications data will suffice; i.e. polling and ACK messages.
The SC720/SC820 MUST be receiving and transmitting SAFECOM RADIO data (Poll and ACK messages)
for proper setting of the Hang Time. Final selling of the Hang Time can ONLY be performed after
SAFECOM system installation.
3.
Observe the RED CD LED as it cycles ON and OFF a response to each data transfer from the
IT500/SC9000 or the SC4000/SC9000. The RED CD LED will either illuminate STEADY and then
extinguish OR it will DOUBLE-BLINK ON-OFF-ON-OFF at a very fast rate.
•
If the CD LED illuminates STEADY: Slowly back off the HANG pot (R11) in the COUNTER-
CLOCKWISE direction until the RED CD LED starts the fast double-blink illumination.
Then increase the HANG pot (R11) rotation slightly in the CLOCKWISE direction; approximately 15°
(degrees) of rotation. The RED CD LED should NOT double-blink.
•
If the RED CD LED is illuminating in DOUBLE-BLINK: Slowly increase the HANG pot (R11) rotation in
the CLOCKWISE direction until the RED CD LED illuminates STEADY for each data transfer.
Then Slowly increase the HANG pot (R11) rotation slightly more in the CLOCKWISE direction;
approximately 150° (degrees) of rotation.
This COMPLETES the setup procedures for the Squelch Threshold, Modulation Deviation and Hang Time.
INSTALL a shorting plug on pin group #8 (JP1 header) at the completion of DK1000 adjustments.
When the shorting plug is installed on pin group #8 (DK1000 JP1 header), for normal SC720/SC820 Data
Repeater communications, the MODE LED will illuminate a BLINKING GREEN.
5.3.4
Output Power
The SC720/SC820 RF Amplifier Output Power is adjustable from a minimum of 2 watts to a maximum of 25
watts. The SC720/SC820 can be configured with a duplexer to allow the transmitter and receiver to connect to
the same antenna. With a duplexer installed, the maximum power output is reduced.
1.
Connect an UHF Watt Meter to the transmit (TX) output, located on the rear panel of the SC720/SC820.
2.
Adjust VR1 (variable resistor #1), on the RF Amplifier, with a tuning tool for the desired Output power. VR1
is located just to the rear of the DK1000 Controller Board.
5.3.5
Setting the Decode Characters
Decode Characters specify the amount of Leading characters the SC720/SC820 must see before activating the
data repeater function. Decode Characters are contained in every packetized message group from an RF2000 or
SC4000.
The Decode Characters are set to three (3) by Bosch, at the factory. Three characters are SET when NO
shorting plug is installed on pin group #5, JP1 header on the DK1000 Controller Board.
© 2004 Bosch Security Systems
If the RF Signal Monitor is NOT capable of dissipating 25 watts of transmitted energy,
terminate the SC720/SC820 TX output with a 50 Ω terminator.
SC720/SC820 Operation and Installation Guide
Page 19
SC720/SC820
System Adjustments
90007-201C
Advertisement
Table of Contents
