TE RBK-X1 - RS232 Data Format

RBK-X1 / RBK-X1C
Rev. B Jun. 2021
29
3.8.2 RS232 Data Format
All data is transmitted in ASCII form. The Data format uses 8 data bits, 1 stop bit, no parity at 9600 baud. Full
duplex TX/RX exists, RTS/CTS is disabled. The Processor recognizes the following fourteen bytes information
packet structure.
BYTE 1
Start of Header (SOH) (always ASCII 01h)
BYTE 2
10’s of seconds (ASCII 30h to 39h (1 to 9))
BYTE 3
1’s of seconds (ASCII 30h to 39h (1 to 9))
BYTE 4
Always a decimal point (ASCII 2Eh)
BYTE 5
0.1’s of seconds (ASCII 30h to 39h (1 to 9))
BYTE 6
Always a NULL (always ASCII 00h)
BYTE 7
Product size code (ASCII numeric – (1 to 3) – see below)
BYTE 8
Product size code (ASCII numeric – (‘_’ or A)– see below)
BYTE 9
100’s of deg. C
BYTE 10
10’s of deg. C
BYTE 11
1’s of deg. C
BYTE 12
Checksum high hex nibble (ASCII value 0–9 A–F) F)
BYTE 13
Checksum low hex nibble (ASCII value 0–9 A–F)
BYTE 14
End of transmission (EOT) (always ASCII 04h)
The checksum hex (A-F) must be in ASCII lower case.
The Processor will ignore all RS232 data until a SOH character is recognized. On receipt of a SOH, 10
additional characters or an EOT character is sought. For each character received (including the SOH) the
longitudinal addition (checksum) is maintained up to and including byte 11. Overflow of the checksum beyond
a byte boundary is discarded; This single byte checksum is converted to two ASCII characters and compared
with bytes 12 and 13 of the received packet.
The processor responds 100ms after receipt of the above data packet with either a single ACK
(acknowledgement) (ASCII 06h) or a NAK (not acknowledgement) (ASCII 15h) character. An ACK response
will occur providing the following verifications are met:
a) The checksum Byte compares.
b) The packet format meets the above defined format. (i.e., The decimal point and null characters occur
in the correct positions and the expected numeric values represented by ASCII 30–39 are present).
Failure to meet these requirements results in the processor responding with a NAK. The only exception
unchecked is product size value.
The two ASCII values designated product size are unchecked as part of the receive protocol other than being
included in the checksum calculation (i.e. any data received in these positions will not result in NAK response).
However, the software will only display product sizes for the following received ASCII characters in these
positions: 1_/2_/3_/3A (where _ is an ASCII null (00h)). Any other data received results in a blank product size
display.