Sdmcd16Ac Instruction; Sdmspeed Instruction - Campbell SDM-IO16 User Manual

SDM-IO16 16 Channel Input/Output Expansion Module

6.2.2 SDMCD16AC Instruction

6.2.3 SDMSpeed Instruction

10
Code Description
0 Output logic low
1 Output logic high
2 Input digital, no debounce filter
3 Input switch closure 3.17 msec debounce filter
4 Input digital interrupt enabled, no debounce filter
5 Input switch closure interrupt enabled 3.17 msec,
debounce filter
6 Undefined
7 Undefined
8 Undefined
9 No change
Mult, Offset The Mult and Offset parameters are each a constant, variable,
array, or expression by which to scale the results of the
measurement.
All but the oldest versions of the CR5000 operating system also support the
SDMCD16AC instruction that can be used to control the SDM-IO16 for output
mode only. This instruction should only be used if backward compatibility is
required, as only the IO16 instruction supports error detection on communication
between the peripheral and the datalogger.
The SDMSpeed instruction is used to change the bit period that the datalogger
uses to clock the SDM data. Slowing down the clock rate may be necessary when
long cable lengths are used to connect the datalogger and SDM devices.
The syntax of this instruction is as follows:
SDMSpeed (BitPeriod)
The BitPeriod argument can be an integer or a variable. If the SDMSpeed
instruction is not in the program, a default bit period is used. If 0 is used for the
argument, the minimum allowable bit period is used. Table 2 shows the default,
minimum allowable, and maximum bit period for each of our CRBasic
dataloggers.
Table 2. Bit Period Values
Default
Datalogger Bit Period
26.04 sec
CR800, CR850
26.04 sec
CR1000, CR1000X
26.04 sec
CR3000
30 sec
CR5000
The equation used to calculate the bit rate depends on the datalogger used. The
datalogger will round down to the next faster bit rate.
Minimum Allowable Maximum
Bit Period Bit Period
8.68 sec
2.2 msec
8.68 sec
2.2 msec
8.68 sec
2.2 msec
8 sec
3 msec