Moog Crossbow VG700MB Series - Manual (Page 20)

VG700M User’s Manual
Page 14 Doc.# 7430-0280-01 Rev. F
3.6 Data Packet Format
In general, the digital data representing each measurement is sent as a 16-bit
number (two bytes). The data is sent MSB first then LSB.
In voltage mode, the data is sent as unsigned integers to represent the range
0 – 5 V.
In scaled and angle mode, the data generally represents a quantity that can be
positive or negative. These numbers are sent as a 16-bit signed integer in 2's
complement format. The data is sent as two bytes, MSB first then LSB.
In scaled and angle mode, the timer information and temperature sensor
voltage are sent as unsigned integers.
The order of data sent will depend on the selected operating mode of the
DMU.
Each data packet will begin with a header byte (255) and end with a
checksum. The checksum is calculated in the following manner:
1. Sum all packet contents except header and checksum.
2. Divide the sum by 256.
3. The remainder should equal the checksum.
The packet also contains the model type configuration number, and the BIT
word output. Please refer to section 3.5.2 for details about the BIT word
processing.
In scaled and voltage mode, each data packet will begin with a header byte
(255) and end with a checksum. The checksum is calculated in the
following manner:
1. Sum all packet contents except header and checksum.
2. Divide the sum by 255.
3. The remainder should equal the checksum.
Tables 3 and 4 show the data packet format for each mode.