CH Tech M222 user manual Operation, Effects of Opening/Closing Relay

C&H Technologies, Inc. <> 445 Round Rock West Drive <> Round Rock, TX 78681 <> www.chtech.com

4.0 OPERATION

The M222 is a register-based instrument that is controlled through a series of I/O registers described in Section 3.2.1. The exact method of accessing and addressing the I/O registers is dependent on the M-Module carrier used to interface the module to your data acquisition or test system. Refer to the carrier’s documentation for information on the address mapping of an M- Module’s I/O registers and to your system software documentation for details on data access.

Typically a high level driver is available to aid in control of the module. Refer to the software driver documentation for instructions on using the driver.

4.1 RELAY OPEN/CLOSE

Each relay channel can be separately controlled with the Relay Register (Reg. 0x14). Writing a 1 to a bit will OPEN the relay (i.e., connect the common terminal to the normally closed terminal) and writing a 0 to a bit will CLOSE the relay (i.e., connect the common terminal to the normally open terminal) as shown in Figure 4.

Figure 4. Effects of Opening/Closing Relay

4.2 INTERRUPTS

The M222 can generate an interrupt request 16ms after a relay is opened or closed indicating that the relay has settled. The interrupt must be enabled in the Control Register (Reg. 0x02).

M-module carriers and system controllers treat the interrupts differently. Refer to your carrier and controller documentation to determine how to properly configure them to handle the M- module interrupt request.

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