Network UPS Tools
Power Devices support
Table of Contents

Communication Specification

Format

RS-232

Baud rate

1200 bps

Data

8 bits

Start Bit

1 bit

Stop Bit

1 bit

Parity

None

"MiniCOL" for MonUPS III (revision 1.2)

Query the status of UPS

Command from PC to UPS

Header (1 byte) Command (1 byte) CSUM

Q

1 (ASCII)

XX

CSUM = 2’s complement of the SUM of the total package

UPS Status Feedback / Shutdown Request

Command from UPS to PC

Header (1 byte) Command (1 byte) CSUM

Q

A - AC Fail

XX

B - Battery Low

C - Both A & B

D - All normal

E - System Shutdown Request

QE - UPS requests for System Shutdown. PC to read three consecutive QE bytes and acknowledge before proceeding with normal shutdown.

System & UPS Shutdown

Step 1. Command from PC to UPS
Header (1 byte) Command (1 byte Integer) CSUM

T

XX (1 ~ 255)

YY

(T - stands for Time-delay, XX is the delay factor in multiple of 10 seconds. So, max. delay time = 42:30 min.)

Step 2. Command from UPS to PC
Header (1 byte) Command CSUM (same as MCOL checksum)

T

A

XX

(TA - stands for Time-delay command acknowledged)

Step 3. Command from PC to UPS
Header (1 byte) Command (1 byte) CSUM

S

D

XX

(SD - stands for shutdown)

Step 4. Command from UPS to PC
Header (1 byte) Command (1 byte) CSUM

S

A

XX

(SA - stands for shutdown acknowledged)

Miscelleaneous

  1. Software to poll the UPS at least 6 times in 2 seconds at program startup to determine if there is "NO COMMUNICATION" and advise "Please check cable connection", etc.

  2. During normal operation, if software receives five checksum error, display "Communication Error".

  3. If there is no response from the UPS, display "No Communication" (after 5 consecutive times) in RED colour (must be outstanding) .

  4. PC to send a UPS shutdown delay TXX and continue sending command until it receives a confirmation command TA before sending ups shutdown command SD. TXX - where XX is a multiple of 10 seconds. So, maximum time delay is 42 minutes and 30 seconds (255 * 10 = 2550 seconds).

  5. Software to have a UPS Off Delay setting screen to accommodate item d. above.

  6. PC must send a SD continuously until it receives a SA from the UPS before system can perform shutdown.

  7. Baudrate = 1200 bps.

  8. Software to perform system shutdown when it receives three consecutive system shutdown request bytes (QE) from UPS. A pop-up message with 5 seconds countdown, and message ‘System powering down, shutdown in 5 seconds’ is to be displayed. The usual system shutdown (with autosaving of files) will take place (to include item d. & f. above).

Shutdown timeline

Shutdown timeline