UPS 250, UPS 300, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supply Caterpillar

MODBUS Register Map

• The UPS Series 300 supports the following protocols: MODBUS/TCP, Class 0 and MODBUS/RTU.

• All registers are read only. The registers are accessed with MODBUS FC3. MODBUS FC3 allows multiple registers to be read.

• There are 5 register groups: System, MMU, Event, Status and Summary.

• Register pairs, shown as (x)(x+1) represent a 32 bit floating point value. The lower numbered register contains bits 15 through 0 of the value. The higher numbered Register contains bits 31 through 16 of the floating point value.

• Registers shown as (x) are 16 bit unsigned quantities.

• References to a register number x is equivalent to MODBUS Register 40000+x.

System Group

The system group pertains to those signals that are common to all of the MMUs that are in a system.

Note 1

Firmware Revisions are shown as: M.mmXY (example: 1.02)

Where:

• M represents the major revision, mm represents the minor revision, X represents the Beta letter and Y represents the Developer Letter. For production code, the Beta and developer letters will be null.

• The Lower 16 bits of the Firmware Revision contain the Beta Letter (upper byte) and Developer Letter (lower byte).

• The Upper 16 bits contain the Major Revision (upper byte) and the Minor Revision (lower byte).

For example, if Register 1 contains 0x7068, and Register 2 contains 0x005a, The firmware revision would be shown as 0.90ph, indicating major/minor revision level of .90, beta version p, developer h.

Note 2

The FPGA revision is shown as X.YZ, where X and Y are numeric and represent the major revisions and the minor revsions. Z is a Beta letter. Example (1.30)

The FPGA revision information can be decoded as follows:

• Major.Minor = (float)Register 3 / 100

• The Beta letter is ASC((Register 4 & 255) + 0x60)

• The Product Family code is contained in the upper 8 bits of Register 4. The product code will always be 0 (zero) for the UPS Series 300. For example, if register 3 contains 0x00A0 and Register 4 contains 0x0008, the FPGA revision would be shown as 1.6h and would indicate a valid Series 300 UPS FPGA.

MMU Detail Group

Event Log Group

The Event Log Group provides a way to read the event log from the UPS Series 300. Events are stored in the internal memory of the UPS according to severity.

• Status Events are normal occurring events that are deemed important enough to store in the event memory, but are not associated with an error condition.

• Notice Events indicate a possible failure or an abnormal condition and should be investigated.

• Alarm Events require immediate attention.

The Message itself is sent as ASCII text in registers 256 through 296 and can be up to 80 characters in length, plus a trailing null. For messages that are less than 80 characters long, the trailing bytes are zeroed. Attempts to read a message index that is greater than the number of indicated messages (in registers 250, 251 or 252) will result in a null string (all message bytes being zeroed).

Refer to the following steps in order to retrieve the event log:

1. Read the number of "All" messages, "Alarm" messages and/or "Warning" messages.

   Refer to the following Registers: 250, 251 and 252.

2. If there are more than 0 messages, set the Command register for the desired message level.

   A reset command should be issued first. Subsequent Advance commands should be issued to progress through all the events.

   If another message is available, the ASCII string area will contain the ASCII characters for the message. The end of the message will be padded with NULL characters. If no other messages are available, the ASCII string area will contain zeros.

Pseudo-coded routines for reading the entire event log, and for periodically checking for new event messages, are shown below. Refer to Illustration 1.

Refer to Table 3 for the Commands for the following Registers: 253, 254 and 255.

Illustration 1	g01084074
Pseudo-coded routine

Note: The UPS Series 300 accumulates events in 2 sectors in flash memory. Each sector can hold 2038 events. When a sector is filled (number of all events = 2038), the most-recent 1440 events are copied to the other (erased) sector before adding new messages to the event log. Therefore, it is possible for the values in registers 250, 251 and/or 252 to suddenly decrease. This must be taken into account when designing code which examines these registers.

Status Group

The Status Group are status registers for the system and MMU. Each bit has a particular meaning for a particular FPGA revision.

Note: The three system status registers are only available on systems with a Systems Cabinet (in other words, systems that can support more than 1 MMU).

Summary Group

The summary group contains some information about each UPS Series 300 unit that is connected via the CAN bus. Register values for MMUs that are not present on the CAN bus are returned as zeros. There are registers for four UPS Series 300 units connected to each other via the CAN bus. Reading registers from a unit that is not connected to the bus will return zeros.