1260-21 User Manual
Module Operation 3-2
Racal Instruments
©
2005
Figure 3-2, Register-Based Mode of Operation
Since the 1260-01T switch controller does not keep track of relay
states during the register-based mode, it is advisable to use
either
the message-based or the register-based mode, and continue to
use the same mode throughout the application program.
In general, the message-based mode of operation is easier to use
with utility software such as the National Instruments VXI
Interactive Control (VIC) program. The message-based mode
allows the user to send ASCII text commands to the 1260-01T and
to read replies from the 1260-01T. In addition, some features, such
as the SCAN list, are available only in the message-based mode of
operation.
The register-based mode provides faster control of relay channels.
In this mode, relay operations are processed in less than 9
microseconds, not counting relay settling time or software
overhead inherent in I/O libraries such as VISA. To determine the
relay settling time, refer to Relay Settling Time in the Specifications
section.
Consult the 1260-01T User’s Manual for a comparison of the
message-based and register-based modes of operation.
PC (MXI)
1260-21
Write value 2 to A24 Address 205001