Service manual

A-1
April 2001
Part No. 001-9800-203
DATA INTERFACE DESCRIPTION
APPENDIX A DATA INTERFACE DESCRIPTION
A.1 GENERAL INFORMATION
A.1.1 INTRODUCTION
This appendix describes the interface signals
provided by 98xx-series low, mid, and high tier and
data transceivers for controlling an external modem or
other accessories such as encoder, decoder,
compandor, and encryption modules.
The interface signals include the data path signal,
data control functions, and power sources. Some
signal lines have optional functions that are selected
by programming as described in *. I/O lines are
programmed on a radio-wide basis which means
the I/O functions are the same for all systems and
groups. Individual systems and groups cannot be
programmed with unique I/O functions.
A.1.2 SOFTWARE VERSION REQUIRED
The interface signals described in this appendix
are available with all 98xx-series transceivers which
have transceiver (Flash) software Version 204 or later.
The software version can be determined by selecting
the test mode as described in Section 3.11.2.
Programming software Version 204 or later is
required to program the interface signals. The software
version number is displayed on the top of most
programming screens.
NOTE: When an external accessory such as an exter-
nal decoder or compandor module is installed, be sure
to program the control line used by the accessory (see
Section 4.9.3) as well as enabling it on the applicable
systems or groups.
A.2 ELECTRICAL SPECIFICATIONS
The electrical characteristics of the various power
supply, receive audio, transmit audio, and control
signals are summarized in Table A-1.
Table A-1 Data Interface Line Electrical Specifications
Name Origin Description
Power Supply Lines
The following power sources are shared with Data Interface connector J301 and internal Option Slots 1 and 2. Therefore,
when determining the total supply current requirement, be sure to consider all options installed in these locations.
Sw Bat Out J301-1 Standard battery voltage output switched by the transceiver power switch. Maximum source
current = 300 mA.
8V Out J301-12 Regulated 8 VDC ±5% output. Maximum source current = 300 mA.
Ground J301-13 Transceiver chassis ground.
Pwr Sw J301-11 This input allows external control of transceiver power. Pulling this line low turns power on and
returning it to a floating condition turns power off (if the front panel power switch is off).
Serial Data Bus Signals
With high tier and data models, the serial data bus can be accessed by intelligent external devices for the purpose of
controlling various transceiver functions. The Serial Bus Protocol is described in Appendix B. This bus is also accessed via
the microphone jack to perform personality programming and transceiver alignment. Those are the only two serial bus func-
tions available with low and mid tier models.
TxD J301-4 Serial transmit data output at TTL levels (unbuffered).
RxD J301-5 Serial receive data input at TTL levels (unbuffered).