User's Manual

Document Number/Ref.-No. Issue
00-6383A01 1.0
(113491 2)
Page 11 of 26
Copyright  2000 by Harris Corporation, RF Communications Division
All rights reserved. No part of this publication may be reproduced or transmitted in
any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in
writing by
Harris Corporation, RF Communications Division,
Rochester, New York, USA
After typing the above line, on the monitor there should be two windows displayed, one window consisting of 25 lines
and one window consisting of 1 line. The window with 25 lines should have some text displayed, this is the window
where the command acknowledgments from the LAAS radios and status reported by the LAAS radios is displayed.
The 1 line window is where commands for the LAAS Host Simulator are typed.
To determine if the Counter I/O ISA card is installed correctly perform the following steps:
1. After connecting the system together as described in section 4.1, start the LAAS Host Simulator and type in
the following command:
rpe 1
2. The LAAS transmitter should power on.
3. If the LAAS transmitter does not power on, then check that all of the cables are plugged in correctly and
that all of the cables are connected securely.
4. After checking the cables type in the following command:
rpe 1
5. If the LAAS transmitter does not power on, repeat the steps in the section 4.3.1 using another valid address
for the Counter I/O ISA card.
6. Repeat steps 1 through 5 of this procedure until the LAAS transmitter powers on or all valid addresses have
been tried. If all valid addresses have been tried and the LAAS transmitter has not powered on then the
Counter I/O ISA card may not be working.
4.3.3 Determining if the LAAS Host Simulator can communicate with the LAAS radios
To determine if the LAAS Host Simulator can communicate with the LAAS radios, perform the following steps:
1. After connecting the system together, as described in section 4.1, start the LAAS Host Simulator and type
in the following commands:
rpe 1
bit v
2. The BIT/Status for both the LAAS receiver and the LAAS transmitter should be displayed.
3. If BIT/Status for both the LAAS receiver and the LAAS transmitter is not displayed, then check that all of
the cables are plugged in correctly and that all of the cables are connected securely. Also check that the
LAAS receiver and the LAAS transmitter are powered on.
4. After checking the cables type in the following command:
bit 1
5. The BIT/Status for both the LAAS receiver and the LAAS transmitter should be displayed.
6. If BIT/Status for both the LAAS receiver and the LAAS transmitter is not displayed then the PC may have a
bad serial port.
4.4 Calibrating Counter I/O ISA card
The Counter I/O ISA card has a 50 PPM crystal oscillator that is used as the time base for the simulated GPS 1 pulse
per second signal. The counters are configured to give one microsecond resolution. This equates to a possible error of
50 microseconds over a one second period. The configuration file for the LAAS Host Simulator contains a calibration
parameter that can be set to reduce this error. Note that the long term aging characteristics of the crystal oscillator
may require that this value be adjusted occasionally to maintain the desired accuracy.