Campbell Scientific CR9000X Measurement and Control System - Manual (Page 254)

Section 7. Measurement Instructions
7-30
SDMIO16 (Dest, Status, Address, Command, ModePorts 16-13, ModePorts
12-9, ModePorts 8-5, ModePorts 4-1, Mult, Offset)
The SDMIO16 instruction is used to set up and measure an SDM-IO16 control
port expansion device. See the SDM-IO16 Manual for more complete details.
Syntax
SDMIO16(Dest, Status,Address,Command, ModePorts 16-13,
ModePorts 12-9, ModePorts 8-5, ModePorts 4-1, Mult, Offset )
Remarks
The ports on the SDM-IO16 can be configured for either input or output.
When configured as input, the SDM-IO16 can measure the logical state of
each port, count pulses, and measure the frequency of and determine the duty
cycle of applied signals. The module can also be programmed to generate an
interrupt signal to the datalogger when one or more input signals change state.
When configured as an output, each port can be set to 0 or 5 V by the
datalogger. In addition to being able to drive normal logic level inputs, when
an output is set high a ‘boost’ circuit allows it to source a current of up to 100
mA, allowing direct control of low voltage valves, relays, etc.
This instruction must NOT be placed inside a conditional
statement or SubScan.
Parameter
& Data Type
Enter SDMIO16 PARAMETERS
Dest
Variable or Array
The Dest parameter is a variable or variable array in which to store the results of the
measurement (Command codes 1 - 69, 91, 92, 99) or the Source value for the Command
Codes (70 - 85, 93 - 98). The variable array for this parameter must be dimensioned to
accommodate the number of values returned (or sent) by the instruction.
Status
Variable
The Status parameter is used to hold the result of the command issued by the instruction. If
the command is successful a 0 is returned; otherwise, the value is incremented by 1 with
each failure.
Address
Constant
The SDM address for the SDM-SIO4 (0-14)
Command
Constant
The Command parameter is used to set up the SDM-IO16. See the SDMIO16 manual or
the CRBasic editor help for more details.
Mode The SIO4 port the instruction applies to.
Constant Cod
e
Port Code Port
1 Output Logic Low 6 Undefined
2 Output Logic High 7 Undefined
3 Input Switch Closure, 3.17 mS debounce
filter
8 Undefined
4 Input Digital interrupt enabled, no debounce
filter
9 No change
5 Input Switch Closure interrupt enabled
Mult, Offset
Constant,
Variable, Array, or
Expression
A multiplier and offset by which to scale the results. A multiplier of one and an offset of 0
are necessary to store the values as received.
NOTE