file: vmcm2_ops.html
11 Feb 2003


The VMCM2 main CPU board (VMLOGR53) normally operates in RS232 mode.
See the VMCM2 Functional Description for info on changing to RS485 operation as well as the RS485 note at the end of this document.

Refer to VMCM2 Commands for full command descriptions.

Getting Started

The following equipment should be available:

Make sure the power supply is OFF. Hook up everything, start the terminal program and get it setup for the correct COM port and 9600 baud, N, 8, 1 operation. Power up and check for power consumption of less than 50 MA at outset. Within a few seconds, you'll see a sign-on message, and once the "Running" message appears (up to 15 seconds after the initial message), the current consumption typically drops to about 10 MA with the supply set for about 13.5 VDC.


The VMCM2 (like ASIMET) has a communications protocol based on the SAIL (Serial ASCII Interface Loop) protocol developed at Oregon State University. The module is interrogated by sending commands with the following format (always with capital letters and terminated with a RETURN <cr>):


The STAT command will display several lines of status info about the instrument.

On power up, the VMCM2 will always come up running and logging as last configured (the STAT command will indicate Sampling GO when the VMCM2 is running).

NOTE that only a subset of the commands is available while the VMCM2 is running. The H command will indicate which commands are available depending upon the GO / STOPPED state of the VMCM2.

Refer to VMCM2 Commands document for full command descriptions.

Deployment Quick Start

For the complete discussion of VMCM2 instrument preparation for deployment, refer to the VMCM2 Instrument Prep document.

The important steps are:

RS232 to RS485 converters