54-0215 Rev. C
7
2 Digital 100 Hz Asynchronous Interface
2.1 Description
(KVH Part No. 02-1222-01)
Connector pins 9 (transmit) and 10 (receive), with ground pin 11, provide an
asynchronous serial interface to the gyro. This interface has the following characteristics:
Type: RS-232
Baud Rate:
38,400 Baud
Parity: None
Data Bits:
8
Stop Bits:
1
Flow Control: None
Both transmit and receive functions are available with this interface. Since transmit (Tx)
and receive (Rx) designations refer to the gyro as the source, “transmit” is an output from
the gyro, and “receive” is an input to the gyro. The “transmit” output has the following
format:
Output Burst Rate:
100/second
(approximate, see Note 1)
Output Format:
ASCII text consisting of two decimal data words (separated by a
space), followed by a carriage return/line feed sequence:
(-)xxx.xxxxxx y
(-)xxx.xxxxxx
= Data Word 1
y
= Data Word 2
Output Data Word 1:
Three user-selectable formats:
Rate
(in degrees/second) = the average over the interval from the
last output; this is the default mode at power-up
Incremental Angle
(in degrees) = the angular change from the
last output
Integrated Angle
(in degrees) = the rotation angle modulo 360
from an arbitrarily user-chosen zero reference (see “Z” on the
following page)
Output Data Word 2:
BIT; ASCII 1 = “Data Valid,” ASCII 0 = “Fault”
Note 1: The output burst rate may vary, gyro-to-gyro, by ±2 to ±3 percent. There is also a variation over
temperature of approximately ±0.2 percent.
The “receive” input supports several user commands. The next section explains how to
access the maintenance mode and lists the available configuration commands.
