VMCM2 Instrument Checkout and Preparation for Deployment

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 following RS485 note.

Refer to VMCM2 Commands for full command descriptions.

Instrument Checkout

Startup and power consumption check

• Setup per the VMCM2 Operations document.

• Power up the VMCM2 and verify the sign-on message.

• Check that current consumption is approximately 10 MA at 13.5 VDC.

Status check

The VMCM2 should be running (GO mode) for this check.

• At least one minute after power-up (with the VMCM2 running), send a STAT command.

• Does the returned status look normal?

• Check the clock setting.

• Is the logging interval correct? (Usually 60 seconds)

• Is the FLASH memory card recognized correctly?

• Does the main battery voltage look OK? (With default cal constants, it will read about 0.5 V below the actual external supply voltage - there's a protection diode in-line with external power).

• NOTE that the Current Tick value is the number of seconds elapsed in the current logging interval; with the usual 60 second interval, this number will rollover at 60 seconds, indicating that the interval data has just been updated.

Data messages

The VMCM2 should be running (GO mode) for these checks.

• At least one minute after power-up (with the VMCM2 running), send a D command.

• Does the output look reasonable?

• If you moved the rotors, do you see velocity values?

• Move the VMCM2 and wait for another update.

• Send another D command and see if the compass value changed.

• Send an E command.

• Does the output look reasonable? On external power, with no inputs to the first three A/D channels, the first three sets of values will be full scale (4095 counts), the 4th channel will read 0 (no current reading while on external power), and the 5th channel will indicate supply voltage minus about 0.5V due to the protection diode in line with external power.

Configuration commands

The VMCM2 must be stopped (STOP mode) for these checks.

Several parameters on the VMCM2 are configurable, the most important being the instrument address (set by default to VM001) and the record unterval. Additionally, calibration constants for the A/D converter can be set, and a free-format checkout/cal date which displays under the STAT command may be set. All configuration commands, as well as the command to erase the FLASH memory card, are sub-commands under the UOK command. All configuration parameters are stored in EEPROM on the main CPU board. FLASH erasure will be discussed later in this document under Preparation for Deployment.

Always check the following (and set if necessary):

• Confirm that the record interval (RI) is correct - typically 60 seconds.

• Confirm that the A/D calibration values are correct; refer to VMCM2 Functional Descriptions - A/D Converter for information on typical values.

• If you make changes to record interval, calibration constants, instrument address, and/or configuration date, you must save those changes with WRTOK. If you don't want to save the changes, or are confused about what to change, use ABORT to quit without saving any changes and keep the original values.

• Remember that an address change only takes effect after cycling VMCM2 power.

Test mode commands

The VMCM2 must be stopped (STOP mode) for these checks. The rotor and compass tests must be performed with the VMCM2 standing upright (sting UP).

• Test the rotors (TR command); see VMCM2 Functional Description for reference.
  • Make sure the rotors are stationary. Rotor 1 is nearest the endcap.
  • Start the TR command.
  • Spin Rotor 1 for 5 turns CLOCKWISE (positive direction).
  • Hit ESC to terminate the command.
  • The response should indicate:
    • Rotor 1 -> 80
    • Rotor 2 -> 0
  • Making sure the rotors are stationary, start the TR command again.
  • Spin Rotor 1 for 5 turns COUNTER-CLOCKWISE (negative direction).
  • Hit ESC to terminate the command.
  • The response should indicate:
    • Rotor 1 -> -80
    • Rotor 2 -> 0
  • Repeat CW and CCW test for Rotor 2 (farthest from endcap).
  • Rotor 1 and Rotor 2 can be done simultaneously if desired.

  • OPTIONALLY: A similar test for each rotor can be performed starting the TR command, spinning each rotor 5 turns CW then 5 turns CCW, hitting ESC. Rotor counts should equal 0 in this case.

• Test the compass (TC command)
  • Start the compass test command.
  • While watching the positions returned, turn the VMCM2 through 360 degrees and look for reasonable compass positions.
  • Check tilt if desired by aligning the VMCM2 to North and tilting a few degrees N, S, E, W.
  • Hit ESC to terminate the command.

• Test the thermistor pod (TT command); see VMCM2 Functional Description for reference.
  • Start the thermistor pod test command.
  • Look for reasonable temperature readings.
  • Use your hand to warm the thermistor slightly and watch for temperature readings to increase.
  • Hit ESC to terminate the command.

• Test the A/D channels (TA command); see VMCM2 Functional Description for reference.
  • Start the A/D test command.
  • Look for reasonable output readings. With external power applied to the VMCM2 and no devices connected to CH1 thru CH3 inputs, the first 3 channels will usually read full scale (4095 counts), the 4th channel should read 0, and the 5th channel should read approximately 0.5V less than the applied external supply voltage.
  • Hit ESC to terminate the command.

FLASH card commands

The VMCM2 must be stopped (STOP mode) for these checks. See FB and FR commands for reference.

• To look at a record in FLASH memory, send the FR command.
• Enter the start record number (default is record #1) and hit ENTER. The record is displayed; any key other than X displays the next record.
• Hit X to quit reading records.
• To determine what record number you might want to enter, use the STAT to determine the last record number.

• To look at any block of memory as just raw (HEX-ASCII) data, send the FB command.
• Enter the start block number (default is block #1) and hit ENTER. The block is displayed; any key other than X displays the next block.
• Hit X to quit reading blocks.
• Note that when looking at raw records (block 257 and above), an A5 A5 hex tag appears near the end of each record. See VMCM2 Record Format for reference.

      Erasing the FLASH memory card

• Don't do this unless you are sure you mean it! Once the FLASH card is erased, everything on it is gone forever....
• To erase a FLASH card, you must first enter the UOK command. The FLASH card is erased by a UOK sub-command to make it harder to do by accident!.
• Enter the FEOK command, and if you're sure, respond with a capital Y to erase. Any other response will abort the erase.
• On completion, a STAT command should indicate 0 records used. A check with the FR command should show a characteristic pattern resulting from all memory locations in FLASH being set to FF hex. The FB command will show all FF hex everywhere.

Preparation for Deployment

The following procedures are the minimum necessary GO - NOGO tests and final prep for the VMCM2 instrument. ALWAYS do at least these tests before putting the VMCM2 in the water!

These tests can be performed with a bench power supply set to 13.5 volts.

1. Unbolt and remove the housing.

2. Setup per the VMCM2 Operations document.

3. Power up the VMCM2 and verify the sign-on message.

4. Check that current consumption is approximately 10 MA at 13.5 VDC.

5. At least one minute after power-up (with the VMCM2 running), send a STAT command.

6. Look for reasonable response.

7. Set your watch or clock to accurate UTC. Type in a time a few seconds in advance of the actual time; i.e. at 14:25:00, type #VM001CLOCK2002/01/15 14:25:15 where the 2002 is the year, 01 is the month, 15 is the day, 14 is the (UTC)hour, 25 is the minutes, and 15 is the seconds. DO NOT hit ENTER yet. The time is entered when you hit the ENTER key. Wait until the correct time and then hit ENTER.

8. Send a STAT command and check the clock setting.

9. Also in the STAT command response, confirm the averaging interval is correct (usually 60 seconds) and the FLASH card is recognized correctly.

10. Erase the FLASH card! Even if the STAT command showed the card as empty, erase the FLASH card! Don't assume you know where the FLASH card has been. 20MB and 40MB cards are usually removed from the instrument for reading data, and other systems with different record sizes will tag used records differently!!! A card used in another system may appear empty when it is NOT - bad data storage WILL result. See Erasing the FLASH memory card earlier in this document.

11. Briefly test the rotors, compass, thermistor pod, and A/D per Test mode commands earlier in this document.

12. Remove the battery rail. Install a new battery with foam pads to insure a tight fit. Re-install the battery rail. Check that the compass and card retainer bars are tight. Lash down any cabling as needed.

13. Check the o-rings and re-install the housing. Purge, install dummy plugs, etc.

14. The VMCM2 is ready to deploy.