Service BulletinChiller Products

©2005 McQuay International 

To: All McQuay Service Locations

Product code: CH

Service Bulletin Number: 20-0554-B

Supercedes: None 

Originator: Kevin Spitzer, Technical Response Center

Date: 10/06/05 

Filed on McQuayBiz: Literature / McQuayService

OITS rev. 2 Memory Map Upgrade Procedure

Anytime the MicroTech II centrifugal controller software is upgraded, the OITS memory mapping table

(plan.csv) must be upgraded as well. The reason for this requirement is that whenever the MicroTech II

software is modified, the memory addresses also get modified. These memory addresses tell the OITS

 panel where to get specific data for such things as Suction, Discharge, Oil Pressure, Compressor amps,

Alarms and other important parameters. Failure to upgrade the memory map table will result in incorrect

data being displayed.

The following procedure is for upgrading the memory mapping file for the new OITS rev. 2 style display

using a USB memory stick.

Equipment Required

1) One USB memory stick with the updated plan.csv file loaded into its root directory.

(256K or larger – preferably with Light Emitting Diode (LED) located on end for easy viewing)

Procedure

1. Follow this procedure after you have programmed the MicroTech II controllers. (Refer to Service

 Bulletin Number 20-0352-B for instructions on upgrading the software for the MicroTech II

controllers.)

2. Plug the USB memory stick into one of the USB ports located on the OITS’s computer board

(see below). Wait a few minutes (at least 2) before proceeding to next step so as to allow the

OITS computer to recognize the USB memory stick. The LED on the USB memory stick should

 be at a steady state condition (ON and not blinking) before proceeding to next step.

 

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3. On the OITS display, access the SERVICE screen. You can access the SERVICE screen from the

main unit view screen by pressing the key twice.

4. Verify that the nodes (OITS, unit, and compressor controllers) indicators are green. This

indicates that communication is occurring through the UCM (Universal Communication

Module).

Should be green

(Example of dual compressor unit addressed as Chiller A)

5. Once it is verified that the UCM is communicating with the nodes, press the

key.

6. Observe on the SERVICE screen in the lower left hand corner, above the “LOAD UCM” key,

what versions of software are being displayed.

Checksum (not shown)

Software version (values shown are for reference only)

When the OITS has finished transferring the memory map file from the USB memory stick

(about 45 seconds), the software version adjacent to UCM will match the unit and compressor

controller’s software version.

7. Once the above is confirmed remove the USB memory stick.

You are done.