PNI Legacy Comm Board - Manual (Page 7)

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Page 7 of 42
Hardware Modes
The CommBoard provides a serial interface to PNI’s sensor modules. Its purpose is to translate a serial
command from a host system into the appropriate SPI command. If the sensor module does not support
the command, it will return the appropriate error code. Otherwise, it will return the associated data. See
the applicable PNI module data sheet for specific information on communication and control using the
SPI interface.
•
RS-232 mode uses software handshaking to communicate.
o
Xon = ^Q = 0 x 11 (okay to send data)
o
Xoff = ^S = 0 x 13 (stop sending data)
•
RS-485 mode is only Half-Duplex.
o
The Continuous Output (go) command is not allowed since Half-Duplex implies queried
responses only.
o
The CommBoard acts as a Slave when the JMP1 is removed.
Example
!FF00$C194.74X-106.00Y-403.00Z98.00:E200*1E
!DdSs${data}*
Table 7: Hardware Modes
! RS-485 data delimiter
Dd Destination address
Ss Source address
$ Start data delimiter
{data} Selected data output
* End data delimiter
Checksum
End of message based on eol variable or or
NOTE:
The query and response format must match. All examples in this manual show the query and response
of the RS-232 mode. When using RS-485 just add the RS-485 data delimiter, destination address,
source address and checksum, to the examples shown.
Checksum
The CommBoard uses a XOR checksum method from the beginning of the string up to, but not
including, the end data delimiter (“*”). Examples:
RS-232 RS-485
Sent Command
id?
(no checksum required) !00ff$id?*37
Reply $id=3*27 !00ff$id?*06
CommBoard
Specifications