Modbus Registers Tables

General Description

The following chapters describe the Modbus registers of the ETV trip system and the Modbus registers of the modules connected to it. These registers provide information that can be read, like electrical measures, protection configuration, and monitoring information. The command interface enables the user to modify these registers in a controlled way.

The presentation rules of the Modbus registers are as follows:

• For each module, the registers are grouped in tables of logically related information, according to the module they relate to:

  • ETV trip system (refer to ETV Trip System Registers)

  • BCM ULP module (refer to BCM ULP Module Registers)

  • IO module (refer to IO Module Registers)

  • IFM interface (refer to IFM Interface Registers)

• For BCM ULP module, the files are described separately (refer to BCM ULP Module Files).

• For each module, the commands are described separately:

  • ETV trip system (refer to ETV Trip System Commands)

  • IO module (refer to IO Module Commands)

  • IFM interface (refer to IFM Interface Commands)

To find a register, use the ordered list of the registers with a cross reference to the page where these registers are described (refer to Appendix A: Cross References to Modbus Registers).

Table Format

Register tables have the following columns:

• Address: a 16-bit register address in hexadecimal. The address is the data used in the Modbus frame.

• Register: a 16-bit register number in decimal (register = address + 1).

• RW: register read-write status

  • R: the register can be read by using Modbus functions  W: the register can be written by using Modbus functions

  • RW: the register can be read and written by using Modbus functions

  • RC: the register can be read by using the command interface

  • WC: the register can be written by using the command interface

• X: the scale factor. A scale of 10 means that the register contains the value multiplied by 10. So, the real value is the value in the register divided by 10. For example, register 1028 contains the I1 current unbalance (refer to Current Unbalance). The unit is % and the scale factor is 10. If the register returns 38, this means that I1 current unbalance is 38/10 = 3.8 %.

• Unit: the unit the information is expressed in.

• Type: the encoding data type (see data type description below).

• Range: the permitted values for this variable, usually a subset of what the format allows.

• Description: provides information about the register and restrictions that apply.

Data Types

Big-Endian Format

INT32, INT32U, INT64, and INT64U variables are stored in big-endian format: the most significant register is transmitted first, the least significant register is transmitted at last place.

Example

The total active energy is an INT64 variable coded in registers 32096 to 32099.

If

• register 32096 = 0

• register 32097 = 0

• register 32098 = 70 (0x0046)

• register 32099 = 2105 (0x0839)

then the total active energy is equal to 4 589 625 Wh = 0x2⁴⁸ + 0x2³² + 70x2¹⁶ + 2105x2⁰

Data Type: FLOAT32

Data type FLOAT32 is represented in the single precision IEEE 754 (IEEE standard for floating-point arithmetic). A value N is calculated as indicated below:

N = (-1)^S x 2^E-127 x (1+M)

Example:

0 = 0 00000000 00000000000000000000000

-1.5 = 1 01111111 10000000000000000000000

with:

• S = 1

• E = 01111111 = 127

• M = 10000000000000000000000 = 1x2^-1 + 0x2^-2 +...+ 0x2-²³ = 0.5

• N = (-1) x 2⁰ x (1+0.5) = -1.5

Data Type: MOD10000

MOD10000 corresponds to n + 1 registers in the INT16 format. Each register contains an integer from - 9999 to 9999. A value V representing n + 1 registers in MOD10000 format is calculated as indicated below:

V = sum(R[x] + R[x+1] x 10000 +...+ R[x+n] x 10000ⁿ), where R[x] is the value of the register number x.

For example, to calculate the active energy Ep coded in 4 registers:

• register 2000 = 123 so R[x = 2000] = 123

• register 2001 = 4567

• register 2002 = 89

• register 2003 = 0

So Ep = R[2000] + R[2001] x 10000¹ + R[2002] x 10000² + R[2003] x 10000³

= 123 + 4567 x 10000 + 89 x 10000² + 0

= 8 945 670 123 kWh

Data Types: DATE and XDATE

This table presents DATE (registers 1 to 3) and XDATE (registers 1 to 4) data types:

For example, if the current date of BCM ULP coded in four registers is:

• register 679 = 0x0513

• register 680 = 0x700A

• register 681 = 0x222E

• register 682 = 0x0358

Then the current date and time of the BCM ULP is 19/05/2012 (May 19, 2012) at 10 hours, 34 minutes, 46 seconds, and 856 milliseconds.

Because:

• 0x0513

  • 0x05 = 5 (months)

  • 0x13 = 19 (days)

• 0x700A

  • 0x70 = 112 (years)

  • 0x0A = 10 (hours)

• 0x222E

  • 0x22 = 34 (minutes)

  • 0x2E = 46 (seconds)

• 0x0358 = 856 (milliseconds)

Data Type: DATETIME

DATETIME is a data type used to code date and time defined by the IEC 60870-5 standard.

Quality of DATETIME Time-Stamps

The quality of time-stamps coded with the DATETIME data type can be indicated in the register following the 4 registers of the time-stamp.

In this case, the time-stamp quality is coded as follows:

Quality of Bits in Registers

The quality of each bit of a register coded as INT16U data type as an enumeration of bits can be indicated in the register preceding the register.

Example:

The quality of each bit of the register 32001, circuit breaker status, is given in the preceding register, 32000.

The quality of the data corresponding to the bit 0 of register 32001, OF status indication contact, is given in the bit 0 of register 32000:

• bit 0 of register 32000 = quality of OF status indication

• bit 0 of register 32001 = OF status indication contact

Data Type: ULP DATE

ULP DATE is a data type used to code date and time. This table presents the ULP DATE data type.

ULP Date Counter

The date in ULP DATE format is counted in number of seconds since January 1, 2000.

In case of a power loss for an IMU module, the time counter is reset and will restart at January 1, 2000.

If an external synchronization occurs after a power loss, the time counter is updated and converts the synchronization date to the corresponding number of seconds since January 1, 2000.

ULP Date Conversion Principle

To convert the date from number of seconds since January 1, 2000, to current date, the following rules apply:

• 1 non-leap year = 365 days

• 1 leap year = 366 days

  Years 2000, 2004, 2008, 2012,...(multiple of 4) are leap years (except year 2100).

• 1 day = 86,400 seconds

• 1 hour = 3,600 seconds

• 1 minute = 60 seconds

Follow the steps in the below table to convert the date from number of seconds since January 1, 2000, to current date:

ULP Date Conversion Example

Registers 2900 and 2901 return the date in number of seconds since January 1, 2000. Register 2902 returns the complement in ms with the quality of the date.

Notes

• The type column tells how many registers to read to get the variable. For instance INT16U requires reading one register, whereas INT32 requires reading two registers.

• Some variables must be read as a block of multiple registers, like the energy measurements. Reading the block partially results in an error.

• Reading from an undocumented register results in a Modbus exception (refer to Modbus Exception Codes).

• Numerical values are given in decimal. When it is useful to have the corresponding value in hexadecimal, it is shown as a C language type constant: 0xdddd. For example, the decimal value 123 is represented in hexadecimal as: 0x007B.

• For measures that depend on the presence of neutral as identified by register 3314 (refer to System Type), reading the value returns 32768 (0x8000) if not applicable. For each table where it occurs, it is explained in a footnote.

• Out of order and not applicable values depend on the data type.