XGS-600 Gauge Controller
DRAFT 4/15/14
77
Appendix C. BCD Serial Commands
The response time to serial command inquiries is approximately 10 msec and is defined as
the time between receiving the last query character to transmission of the first response
character. Serial queries occurring more frequently than 10 per second will compromise
system responsiveness.
C.1 Command Format
❑ The data format consists of a start bit (logic 0), 8 data bits, and a stop bit (logic 1).
There is no parity bit.
❑ All commands are one byte commands that apply to the whole unit or are followed
by one or more bytes to indicate the gauge the command is operating (Card
Information Byte) and the desired pressure or parameter setting, if necessary.
❑ If an invalid command is received the XGS600 returns a one byte response of FFh.
❑ If a command is not completely received within approximately 5 seconds, the
XGS600 ignores the command in process and expect a fully new command.
❑ In all of the following, the suffix H indicates hexadecimal notation.
C.1.1 Card Information Byte
This byte tells the controller which gauge channel to act on for reading pressure or changing
status.
The card information byte consists of two nibbles. The first nibble is the board base address
and is determined by the slot in which the board is installed. The second nibble is a 0 for
HFIG and IMG boards and the Convectorr Gauge number (1,2,3…) for a Convection board.
Since the XGS-600 board installation rules are different than Multigauge, the base address is
not the same as the slot number. This allows maximum backwards compatibility with old
applications. The mapping of slots and addresses is shown in Table C-1 (in the following
instructions slot # refers to the XGS-600 physical slot):
Table C-1 Card Information Byte Mapping
XGS-600 Slot # BCD base Address
12
23
34
45
To Next Page
Loading...
