Communication Specifications

Introduction

The following specifications describe the capacities of the BMENOP0300 module.

Data In versus Data Out

The terms data in and data out, as used in this topic, refer to the flow of data from the point of view of the BMENOP0300 module, and vary depending on the role of the device as client or server.

Data In: The BMENOP0300 module receives a data update from its connected devices, then synchronizes data with the CPU:
- As server: The BMENOP0300 module receives a command from a control object or GOOSE.
- As client: The BMENOP0300 module receives a report/GOOSE response to a previous read request.
Data Out: The BMENOP0300 module receives a data update from the CPU, then propagates the data among its connected devices:
- As server: The BMENOP0300 module sends a buffered report, unbuffered report, or GOOSE.
- As client: The BMENOP0300 module issues a control object or polling command, a command for a buffered report, unbuffered report, or GOOSE.

IEC 61850 Messaging Specifications

The BMENOP0300 module presents the following IEC 61850 messaging features:

Feature	Client	Server
maximum number of concurrent IED connections	32	—
maximum number of words for data in flow variables	4,0001,2,4	4,0001,2,4
maximum number of words for data out flow variables	4,0002,3	4,0002,3
maximum number of simultaneous client connections	—	16
maximum number of data sets	—	68
maximum number of data attributes per data set	—	256
maximum number of virtual logical devices within an IED	—	16
maximum number of report control blocks within an IED	—	64 total buffered plus unbuffered report control block instances
maximum number of instances of a single buffered control block	—	8 (serving 8 clients)
maximum buffer size of each buffered control block	—	16k bytes
maximum number of control blocks for GOOSE publishing	—	4 control blocks
maximum number of GOOSE control block subscriptions	—	32 for both server/client
minimum interval of GOOSE publishing	—	20 ms
maximum number of inputs in a GOOSE data set	—	256
maximum size of GOOSE message	—	1520 bytes
time stamping resolution	—	1 ms
1. The maximum number of input words includes the sum of client and server input words. 2. The maximum number of variables depends on the data types included in the application because the lengths of different data types varies. 3. The maximum number of output words includes the sum of client and server output words. 4. Module memory contains the most current (real-time) value for data in flow.

Explicit Messaging Specifications

The BMENOP0300 module presents the following Modbus TCP explicit messaging features:

Feature		Capacity
Client
	maximum number of simultaneous connections	16 connections
	maximum number of concurrent requests	16 requests
Server
	maximum number of concurrent requests	12 requests
	maximum number of simultaneous connections	32 connections
Maximum Message Size
	read	250 bytes (125 words) excluding header
	write	240 bytes (120 words) excluding header

Comparing Standard Data Types: Control Expert and IEC 61850 Data Types

The following list presents IEC 61850 standard data types and the comparable data type used by Control Expert:

Control Expert Standard	Comparable IEC 61850 Standard
Data Type	Data Type	Support by
Data Type	Data Type	Server	Client
WORD	BITSTRING	√	√
BOOL1	BOOLEAN	√	√
WORD	CODED ENUM	√	√
WORD	Dbpos/Tcmd	√	√
WORD	ENUMERATED	√	√
REAL	FLOAT	√	√
INT	INT8	√	√
BYTE	INT8U	√	√
INT	INT16	√	√
UINT	INT16U	√	√
DINT	INT32	√	√
UDINT	INT32U	√	√
Timestamp	TIME_850_FORMAT	√	√
1. In Control Expert, a BOOL occupies one BYTE.

BITSTRING

IEC 61850 supports trigger, option, coded enum, and quality report elements in BITSTRING format. Control Expert maps BITSTRING to the WORD data type. In each of the following structures, Bit0 is the most significant bit.

Trigger option of report structure: The following bits indicate the stated trigger value when equal to 1:

Bit0	Bit1	Bit2	Bit3	Bit4	Bit5	Bit6	Bit7
Reserved	Data-change	Quality-change	Data-update	Integrity	General-interrogation	0	0

Option field of report structure: The following bits indicate the stated option value when equal to 1:

MSB	Bit0	Bit1	Bit2	Bit3	Bit4	Bit5	Bit6	Bit7
MSB	Reserved	Sequence-number	Report-timestamp	Reason for inclusion	Data-set-name	Data-reference	Buffer-overflow	EntryID
LSB	Bit8	Bit9	Bit10	Bit11	Bit12	Bit13	Bit14	Bit15
LSB	Conf-revision	Segmen-tation	–	–	–	–	–	–

Quality element structure: The following bits indicate the stated quality value when equal to 1:

MSB	Bit0	Bit1	Bit2	Bit3	Bit4	Bit5	Bit6	Bit7
MSB	Validity: 00 = good 01 = invalid 10 = reserved 11 = questionable		Overflow	Out-of-range	Bad-reference	Oscillatory	Detected failure	Old-data
LSB	Bit8	Bit9	Bit10	Bit11	Bit12	Bit13	Bit14	Bit15
LSB	Inconsis-tent	Inaccurate	Source: 0 = process 1 = substituted	Test	Operator-blocked	–	–	–

CODED ENUM

Coded Enum definition from IEC 61850-8-1, only low byte is valid for DPS/DPC:

MSB	Reserved
LSB	0x00 = Intermediate state 0x40 = Off 0x80 = On 0xC0 = Bad-state

Coded Enum definition from IEC 61850-8-1, only low byte is valid for BSC/BAC:

MSB	Reserved
LSB	0x00 = Stop 0x40 = Lower 0x80 = Higher 0xC0 = Reserved

Dbpos/Tcmd

Dbpos (double position) definition from IEC 61850-8-1:

MSB	Reserved
LSB	0x00 = Intermediate state 0x40 = Off 0x80 = On 0xC0 = Bad-state

Tcmd definition from IEC 61850-8-1:

MSB	Reserved
LSB	0x00 = Stop 0x40 = Lower 0x80 = Higher 0xC0 = Reserved

Custom Data Types

The BMENOP0300 module also provides the following custom data types, which are used to support module DDTs:

IED_ERT_BUF
IIED_EVT_M
IED_EVT_Q
IED_RPT
TIME_850_FORMAT

Refer to the presentation of each custom data type elsewhere in this document for a description of its structure.