Remote Control - PEAK COMMUNICATIONS P7001R Installation And Operating Handbook

5. REMOTE CONTROL

The unit transmits and receives data serially in an asynchronous format using the
standard ASCII character set. The serial data consists of message frames composed of
the following message characters: STX, BYTE COUNT, DEVICE ADDRESS,
INSTRUCTION, BODY, CHECKSUM, ETX. All characters are compulsory except for
the message body. The presence of a message body is determined by the message
type (INSTRUCTION). The total number of message characters in a message frame
may range from a minimum of 6 to a maximum of 255.
The remote control follows the following protocol: (in byte form)
[STX] start of message character #02.
[B] char defining how many characters are in the message including the STX & ETX
parts.
[A] Address of unit. Address ranges from ASCII character 001 to 255.
[I] Instruction number.
See List below
[MESSAGE]
Numerous characters from length 0 upwards.
[CHKSUM]
The checksum is used to verify the accuracy of the message frame. The
checksum is defined as the summation of all the bytes in the message, beginning
with the 3rd byte (DEVICE ADDRESS) and extending through the body of the
message, ending with the last byte before the checksum. The total of the bytes is
then ANDed with 255 so that the checksum is truncated to a single byte.
[ETX] End of transmission character #03
All message to and from the unit follow the above protocol with a character format of 8
data bits, one stop bit, no parity, baud rate 19200, 9600, 4800, 2400, 1200 or 300. Note
that all numeric values are shown as decimal.
Page 22 P7001R & P7002R Series Converters