Signametrics SMX4030, Operator'S Manual

Page: 47 / 61

47 Signametrics
required for accessing the selected channel. This command is applicable in the following
configurations:
TwoWire , FourWire , SixWire , TwoGroups, and FourGroups . It opens
and closes all relays within one t-Actuation. Issuing this command will prevent the
execution of any other function for a time specified in the currently set Actuation time, t-
Actuation.
Parameter Type/Description
iScan int Identifies the Scanner. Numbered starting with zero.
iChan int Channel number Range: 1 to 35 depending on Scanner type and
set configuration. 0 causes opening of all channels in a group.
Return Value Integer code.
Value Meaning
SCAN_OKAY
Operation successfully completed.
Negative Value Error code
Example
SCANSelectChannel(0, 3); // Select a channel
DMMRead(0, @val); // measure input at Channel 3
SCANSelectChannelCmd
H/W access Command

Polled Command

Description Polled select channel command.
#include “SMX4032.H”
int SCANSelectChannelCmd(int iScan, int iChan)
Remarks
This is the polled version of the SCANSelectChannel function. It opens all channels in a
group, then closes channel number iChan . This is a polled function. It sends a command
to the Scanner but unlike SCANSelectChannel , unlike the SCANSelectChannel
function it does not wait for completion of the operation. SCANReady must be used in
order to verify the selected channel was closed and the scanner is ready for a new
command. The time to ready is dicated by t-Actuation. It is necessary for
SCANReady
to return TRUE once for proper operation. For instance, if the actuation time is set to
10ms, and a wait of 100ms it taken following the execution of the
SCANSelectChannelCmd , it should not be assumed the scanner is ready. SCANReady
must be used and return TRUE to proceed. SCANReady not only checks for readiness,
but it also clears some registers in preparations for the next command. It is important to
note that the
SCANSelectChannelCmd is context sensitive and depending on the
current configuration will function differently. See SCANSelectChannel command for
details. This command is limited to the following configurations: TwoWire , FourWire ,
SixWire , TwoGroups and FourGroups .
Parameter Type/Description
iScan int Identifies the Scanner. Numbered starting with zero.
iChan
int Channel number Range: 1 to 40 depending on Scanner type and
set configuration
Return Value Integer code.