Sierra Instruction Manual Smart-Trak
®
2 Series 100
95
GasSpanEvent(current gas only), SetpointIndexEvent, OuputIndexEvent,
UnitIndexEvent, ValveFlashEvent, StreamEvent, SyncEvent
ASCII STRING COMMANDS
'?Sync + CRC + cr' Version 2.xx read command
Returns ASCII string 'Sync + "" + CRC + cr'
SyncEvent returned last to indicate all events have been sent
CRC=redundancy check bytes; cr=carrage return byte.
ZERO
DESCRIPTION
ZERO sets the flow offset value to a zero flow reading. Warning: All flow must be shut
off, the unit needs to be at pressure with the gas being used.
ASCII STRING COMMANDS
'!Zero + "" + CRC + cr' Version 2.xx write command
CRC=redundancy check bytes; cr=carrage return byte.
RESET_ZERO
DESCRIPTION
Reset zero flow offset value to zero
ASCII STRING COMMANDS
'!Rezr + "" + CRC + cr' Version 2.xx write command
Returns ASCII string 'Rezr + "" + CRC + cr'
CRC=redundancy check bytes; cr=carrage return byte
CRC CALCULATIONS
Below is the routine used to calculate the CRC bytes in C#.
Comments are between the /* */.
private
static
uint
CalcCRC(
byte
[] cmnd)
/* cmnd is a byte array containing the command ASCII string … cmnd[]=”Sinv2.000” */
/* An unsigned 32 bit integer is return to the calling program */