Sine Systems RFC-1/B Instruction Book

/4\ LURRN1NG!
L ----- 4 Some older equipment provides telemetry outputs
which can be elevated as much as several hundred volts above ground. Do not
connect this type of telemetry source to the RP-8 panels!
If the RFC- 1 is to be used in ''parallel" with another remote control, it is usually quite feasible
to simply parallel the corresponding telemetry sources. There are some potential problems to
consider, however. First, be sure the telemetry sources fall within the voltage guidelines
discussed above. Second, calibration of the original remote control will be necessary after the
RFC-1 connections are made since an additional load will have been placed on the telemetry
sources. Third, the RFC-1, and all other remote controls for that matter, present a slightly
different load impedance depending on whether a particular channel is selected. For this
reason, do not calibrate or read one remote control with the other remote control "sitting" on
the same channel. Nothing catastrophic will happen, but, depending on the impedance of the
telemetry source, inaccurate telemetry readings may result and the Telephone Alarm System
may be tripped unnecessarily.
Status Connections
The RFC-1 has the feature that any telemetry channel can also be a status channel. To
understand how to accomplish this it is helpful to first understand the telemetry output
protocol. The RFC-1 has the capability to read telemetry over a range of 0000 to 2040. If the
reading is between 0003 and 2039, the telemetry is spoken as four digits. If the reading is
0002 or lower, the words "Status: Off' are spoken. If the reading is 2040 (or over-range) the
words "Status: On" are spoken. The following illustration shows how status indications can
be accomplished:
external to RP-8 panel on RP-8 panel
calibration pot
To differential
amp in RFC-1
TELEMETRY reed relay
terminal
("on" when channel selected)
external contact
to be monitored
Power Supply
+ 1
----------- O O |
Y —
+ 50K<
(9 volt DC, typical)
IK?
—
WF
When the external contacts are closed, the telemetry reading for the channel will be "Status:
On" and when the contacts are open the telemetry will be "Status: Off." The power supply
shown in the illustration can be a simple "wall-plug" battery eliminator which can supply
anywhere from 6 to 12 volts DC. An example of this is a Radio Shack 273-1455. A single
power supply can furnish power for many status contacts. The external IK ohms resistor is
added to more quickly discharge the 10 pF capacitor on the RP-8 panel. Otherwise about 5
3.00.2
Installation page 5.5

Sine Systems RFC-1/B Specifications

General

Brand	Sine Systems
Model	RFC-1/B
Category	Remote Control
Language	English