Campbell Hausfeld Serial I/O Interface SDM-SIO4 - Manual (Page 48)

SDM-SIO4 User Guide
5-18
;get data from SDM-SIO4 and put into locations 1 and 2.
3: SDM-SIO4 (P113)
1: 1 Reps
2: 0 Address
3: 1 Send/Receive Port 1
4: 4 Command
5: 0 1st Parameters
6: 0 2nd Parameters
7: 2 Values per Rep
8: 1 Loc [ number ]
9: 1.0 Mult
10: 0.0 Offset
;At zero minutes into a 10 minute interval set the output
;so that the data from the sensor will be stored into
;final storage.
4: If time is (P92)
1: 0 Minutes (Seconds --) into a
2: 10 Interval (same units as above)
3: 10 Set Output Flag High (Flag 0)
;Time stamp.
5: Real Time (P77)
1: 1110 Year,Day,Hour/Minute
;Instantaneous sample form the sensor.
6: Sample (P70)
1: 2 Reps
2: 1 Loc [ number ]
;Average over the 10 minute interval.
7: Average (P71)
1: 2 Reps
2: 1 Loc [ number ]
*Table 2 Program
02: 0.0000 Execution Interval (seconds)
*Table 3 Subroutines
End Program
5.3.2 Sensors Which Send Data Out Without Prompting
It can be very difficult to acquire data from this type of sensor because of the lack
of synchronisation with the datalogger program.
For sensors which output data relatively slowly data can be collected by using
special features of the input filters which tell the SDM-SIO4 only to recognise the
start and end of data (using the x and X options – see Section 3). These options
only allow the datalogger to collect data once a complete data set has been
received by the SDM-SIO4 (avoiding problems of collection in mid-
transmission). Thus, by polling the SDM-SIO4 using command 1, it is possible to
see if data has been received and if so use a second call of the datalogger
SDM-SIO4 instruction to collect the available data.