Orban OPTIMOD 6200, Operating Manual

Page: 152 / 195

6-10
TECHNICAL DATA Orban Model 6200
1. Remote Interface (Model 6200 OPTIMOD-DAB only) and RS-232
Interfaces
A remote interface connector and circuitry enables remote control of certain operating
modes; Model 6200 OPTIMOD-DAB has eight remote contact closure inputs.
A valid remote signal is a momentary pulse of current flowing through the particular
remote signal pins. Current must flow consistently for 50msec for the signal to be inter-
preted as valid. Generally, the 6200 will respond to the most recent control operation
whether it came from the front panel, remote interface, or RS-232.
Component-Level Description:
26-pin header J101 attaches via ribbon cable to the 25-pin D-connector, which
connects the remote control input signals. The ribbon cable incorporates a ferrite
block to filter out RFI from the signals. The associated opto-isolators (e.g., IC110)
isolate the inputs from the detector circuitry on the 6200. The associated diodes
(e.g., CR102) prevent the opto-isolators from breaking down under a reverse bias.
The outputs of the opto-isolators are inverted and buffered (e.g., by IC118-A) and
latched by tri-state data buffer IC120. When
REMOTE
signal provided to IC120
pin 19 is brought low, IC120 places remote signals on the Z-180 data bus.
The dual RS-232 interface is comprised of 9-pin D-connectors J100 and J104, and
ICs 121 and 123. IC121 and IC123 interface the RS-232 signals with the Z-180
microprocessor.
2. Switch Matrix and LED Indicators
Eleven front panel pushbutton switches are arranged in a matrix, configured as three col-
umns and four rows. These switches are the primary element of the physical user inter-
face to the 6200 control software. The host microprocessor controls the system setup and
function of the DSP according to the switch/rotary encoder entered commands, the AES
Status bits from the Digital Input signal, the RS-232, and the remote control interface
status (Model 6200 OPTIMOD-DAB only); and updates the LED control status indica-
tors accordingly.
Component-Level Description:
S1-S11 are the front panel pushbutton switches. CR11-CR15 are the front panel
LED control status indicators. Via decoder IC102, the host microprocessor Z-180
periodically selects data latch IC3 (on the display board) to drive one of the three
columns in the switch matrix low, then commands tri-state data buffer IC8 (also
on the display board) to read its inputs to determine if any new information is be-
ing received from one or more of the switches in that column. If no switches are
closed, pull-up resistors R25-R28 pull the buffer inputs to +5V. The buffer, in
turn, de-bounces the signals and places the appropriate word on the data bus for
the Z-180 to read. The Z-180 transmits the updated information to data latch IC3
which directly drives the LED Control Status Indicators.
3. LED Meter Circuits