Overview

The CONTROL and DATABUF output parameters define the operation performed by the MBP_MSTR function block. For the Modbus TCP protocol, both the structure and the content of the CONTROL output parameter vary, depending upon the function code.

The structure of the CONTROL parameter is described, below, for each supported function code.

Refer to the Quantum Ethernet I/O System Planning Guide for an example of an MSTR block created in a Control Expert application to read the ports of a dual-ring switch (DRS) to diagnose a sub-ring break.

Control Parameter Routing Register

The CONTROL[5] routing register specifies the source and destination node addresses for network data transfer, and consists of the following 2 bytes:

  • Most Significant Byte (MSB): contains the source node address, for example, the slot number of the 140 NOC 78• 00

  • Least Significant Byte (LSB): contains the destination node address — a value representing either a direct or a bridge address. The LSB is required for devices that are reached through a bridge, for example, an Ethernet to Modbus bridge or an Ethernet to Modbus Plus bridge. The values of the LSB are as follows:

    • If no bridge is used: LSB is set to zero(0).

    • If a bridge is used: LSB contains the Modbus Plus on Ethernet Transporter (MET) mapping index value. This value, also known as the Unit ID, indicates the device to which the message is directed.

The CONTROL[5] routing register:

When the Ethernet communication module acts as a server, the LSB indicates the destination of a message received by the communication module:

  • messages with an LSB value from 0 to 254 are forwarded to and processed by the CPU

  • messages with an LSB value of 255 are retained and processed by the Ethernet communication module

NOTE: Unit ID 255 should be used when requesting diagnostic data from the Ethernet communication module.

Write Data

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

1 = write data

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

Data buffer length

Number of addresses sent to the slave

CONTROL[4]

Starting register

Start address of the slave to which the data is written, in 16-bit words

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]1

IP address

Byte 4 of the IP address (MSB)

CONTROL[7]1

Byte 3 of the IP address

CONTROL[8]1

Byte 2 of the IP address

CONTROL[9]1

Byte 1 of the IP address (LSB)

1. For example, the control parameter handles the IP address 192.168.1.7 in the following order: Byte 4 = 192, Byte 3 = 168, Byte 2 = 1, Byte 1 = 7.

Read Data

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

2 = read data

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

Data buffer length

Number of addresses to be read from the slave

CONTROL[4]

Starting register

Determines the %MW starting register in the slave from which the data is read. For example: 1 = %MW1, 49 = %MW49)

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]1

IP address

Byte 4 of the IP address (MSB)

CONTROL[7]1

Byte 3 of the IP address

CONTROL[8]1

Byte 2 of the IP address

CONTROL[9]1

Byte 1 of the IP address (LSB)

1. For example, the control parameter handles the IP address 192.168.1.7 in the following order: Byte 4 = 192, Byte 3 = 168, Byte 2 = 1, Byte 1 = 7.

Get Local Statistics

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

3 = read local statistics

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

Data buffer length

Number of addresses to be read from local statistics (0...37)

CONTROL[4]

Starting register

First address from which the statistics table is read (Reg1=0)

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]

(not used)

—

CONTROL[7]

CONTROL[8]

CONTROL[9]

Module Response: A TCP/IP Ethernet module responds to the Get Local Statistics command with the following information:

Word

Description

00...02

MAC Address

03

Board Status — this word contains the following bits:

Bit 15

0 = Link LED off; 1 = Link LED ON

Bit 3

Reserved

Bits 14...13

Reserved

Bit 2

0 = half duplex; 1 = full duplex

Bit 12

0 = 10 Mbit; 1 = 100 Mbit

Bit 1

0 = not configured; 1 = configured

Bits 11...9

Reserved

Bit 0

0 = PLC not running; 1 = PLC or NOC running

Bits 8...4

Module Type — this bit presents the following values:

  • 0 = NOE 2x1

  • 1 = ENT

  • 2 = M1E

  • 3 = NOE 771 00

  • 4 = ETY

  • 5 = CIP

  • 6 = (reserved)

  • 7 = 140 CPU 651 x0

  • 8 = 140 CRP 312 00

  • 9 = (reserved)

  • 10 = 140 NOE 771 10

  • 11 = 140 NOE 771 01

  • 12 = 140 NOE 771 11

  • 13 = (reserved)

  • 14 = 140 NOC 78• 00

  • 15...16 = (reserved)

  • 17 = M340 CPU

  • 18 = M340 NOE

  • 19 = BMX NOC 0401

  • 20 = TSX ETC 101

  • 21 = 140 NOC 771 01

04 and 05

Number of receiver interrupts

06 and 07

Number of transmitter interrupts

08 and 09

Transmit_timeout detected error count

10 and 11

Collision_detect error count

12 and 13

Missed packets

14 and 15

(reserved)

16 and 17

Number of times driver has restarted

18 and 19

Receive framing detected error

20 and 21

Receiver overflow detected error

22 and 23

Receive CRC detected error

24 and 25

Receive buffer detected error

26 and 27

Transmit buffer detected error

28 and 29

Transmit silo underflow

30 and 31

Late collision

32 and 33

Lost carrier

34 and 35

Number of retries

36 and 37

IP address

Clear Local Statistics

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

4 = clear local statistics

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

(not used)

—

CONTROL[4]

(not used)

—

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]

(not used)

—

CONTROL[7]

CONTROL[8]

CONTROL[9]

Get Remote Statistics

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

7 = get remote statistics

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

Data buffer length

Number of addresses to be read from the statistics data field (0...37)

CONTROL[4]

Starting register

First address from which the node statistics table is read

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]1

IP address

Byte 4 of the IP address (MSB)

CONTROL[7]1

Byte 3 of the IP address

CONTROL[8]1

Byte 2 of the IP address

CONTROL[9]1

Byte 1 of the IP address (LSB)

1. For example, the control parameter handles the IP address 192.168.1.7 in the following order: Byte 4 = 192, Byte 3 = 168, Byte 2 = 1, Byte 1 = 7.

Clear Remote Statistics

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

8 = clear remote statistics

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

(not used)

—

CONTROL[4]

(not used)

—

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]1

IP address

Byte 4 of the IP address (MSB)

CONTROL[7]1

Byte 3 of the IP address

CONTROL[8]1

Byte 2 of the IP address

CONTROL[9]1

Byte 1 of the IP address (LSB)

1. For example, the control parameter handles the IP address 192.168.1.7 in the following order: Byte 4 = 192, Byte 3 = 168, Byte 2 = 1, Byte 1 = 7.

Reset Module

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

10 = reset module

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

(not used)

—

CONTROL[4]

(not used)

—

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]

(not used)

—

CONTROL[7]

CONTROL[8]

CONTROL[9]

Read/Write Data

The control parameter consists of 11 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

23 = read / write data

CONTROL[2]

Detected error status

Holds the event code (read-only)

CONTROL[3]

Data buffer length

Number of addresses sent to the slave

CONTROL[4]

Starting register

Determines the %MW starting register in the slave to which the data will be written. For example: 1 = %MW1, 49 = %MW49)

CONTROL[5]

Routing register

High byte = Ethernet communication module slot

Low byte = MBP on Ethernet transporter (MET) mapping index

CONTROL[6]1

IP address

Byte 4 of the IP address (MSB)

CONTROL[7]1

Byte 3 of the IP address

CONTROL[8]1

Byte 2 of the IP address

CONTROL[9]1

Byte 1 of the IP address (LSB)

CONTROL[10]

Data buffer length

Number of addresses to be read from the slave

CONTROL[11]

Starting register

Determines the %MW starting register in the slave from which the data is read. For example: 1 = %MW1, 49 = %MW49)

1. For example, the control parameter handles the IP address 192.168.1.7 in the following order: Byte 4 = 192, Byte 3 = 168, Byte 2 = 1, Byte 1 = 7.

Enable/Disable HTTP or FTP/TFTP Services

When HTTP or FTP/TFTP has been enabled using Control Expert configuration tools, an MSTR block can be used to change the enabled state of the service while the application is running. The MSTR block cannot change the state of the HTTP or FTP/TFTP services if the service was disabled using one of the configuration tools.

The control parameter consists of 9 contiguous words, as described below:

Register

Function

Description

CONTROL[1]

Operation

FFF0 (hex) 65520 (dec) = enable / disable HTTP or FTP/TFTP

CONTROL[2]

Detected error status

Holds the event code (read-only). Codes returned include:

0x000 (Success): MSTR block with operational code 0xFFF0 was called and the enabled state of HTTP or FTP/TFTP was changed.

0x5068 (Busy): MSTR block with operational code 0xFFF0 was called within 2 seconds of the previous call (regardless of return code from previous call).

0x4001 (Same state): MSTR block with operational code 0xFFF0 was called to change the enabled state of HTTP and FTP/TFTP to the states they were already in.

0x2004 (Invalid data): MSTR block with operational code 0xFFF0 was called and the data in the control block did not match the specifications.

0x5069 (Disabled): If the HTTP or FTP/TFTP service was already disabled via the Control Expert interface when the MSTR block with operational code 0xFFF0 was called to change the state of the disabled service.

CONTROL[3]

  

Set this register to 1.

CONTROL[4]

CONTROL[5]

Module slot number and destination ID

High byte = Module slot number communication module slot

Low byte = Destination ID

CONTROL[6]

Request mode

Bit 0 (LSB) = 1: Enable FTP/TFTP

Bit 0 (LSB) = 0: Disable FTP/TFTP

Bit 1 = 1: Enable HTTP

Bit 1 = 0: Disable HTTP

CONTROL[7]

  

Set this register to 0.

CONTROL[8]

CONTROL[9]

HTTP, FTP, and TFTP service state changes made by MSTR with operation code FFF0 (hex) are overridden by the configured value when the module is power-cycled or reset and when a new application is downloaded to the module.

Here are some examples:

State Configured By Control Expert

Action attempted using MSTR with operation code FFF0 (hex)

Result

Disabled

Any

MSTR returns detected error code 0x5069 (service was already disabled by configuration)

Enabled

Disable

MSTR returns code 0x000 (success).

  • Another MSTR block action enables the service

    --OR--

  • The module is reset or power-cycled

    --OR--

  • A new application is downloaded with the service disabled by configuration

Enable

MSTR returns detected error code 0x4001 (same state). No change made.