DOCA0172EN-12

Modbus-SL Communication

Presentation

Panel Server Universal and Advanced are Modbus-SL clients and they can be connected to any Modbus-SL server devices. The Panel Server acts as a Modbus gateway and then allows any upstream software such as EcoStruxure Power Monitoring Expert and EcoStruxure Power Operation using Modbus TCP/IP communication to access the Modbus-SL devices.

The Panel Server is also able to collect data from the Modbus-SL devices for publishing to a cloud application or for historization by the energy server in a Panel Server Advanced .

Modbus-SL server devices are connected downstream to the EcoStruxure Panel Server .

For more information, see Modbus-SL functions and Modbus-SL exceptions codes in appendix.

The Panel Server Modbus serial port can be configured in reverse mode (see Modbus-SL Reverse Mode).

Availability

This function is available on Panel Server Universal and Advanced .

Setting the Parameters

NOTICE
IMPAIRED NETWORK PERFORMANCE
Only qualified personnel should modify the Modbus-SL settings. Perform such modifications only after you have read about and understood the Modbus-SL settings.
Failure to follow these instructions can result in loss of network connectivity.
The Modbus-SL communication function is set as follows:
  • With EcoStruxure Power Commission (EPC) software

  • On the EcoStruxure Panel Server webpages, at Settings > Modbus devices > Modbus configuration .

For information about the Modbus registers, see the guide of each Modbus-SL device and DOCA0241EN EcoStruxure Panel Server  - Modbus File for wireless devices.

Modbus Serial Mode Settings

The following table describes the settings and where they are available.

Parameter Description EPC software Webpages
Modbus mode Used to select the configuration of Modbus-SL mode:
  • Client (default setting)

  • Server

Modbus Serial Client Configuration Settings

The following parameters are displayed only when the parameter of Modbus-SL mode is set to Client.

The following table describes the settings and where they are available.

Parameter Description EPC software Webpages
Activation Used to enable/disable the Modbus-SL feature (enabled by default).
Baud rate (bits per sec) Used to set the transmission rate:
  • 1200

  • 2400

  • 4800

  • 9600

  • 19200

    (default setting)
  • 38400

  • 57600

  • 115200

Parity Used to define the parity bit of the transmitted bytes:
  • Odd

  • None

  • Even (default setting)

Number of bits 8 bits. Setting not editable.
Number of stop bits

Used to define the number of stop bits transmitted: 1 or 2 (default setting: 1)

Silent interval (ms)

Used to define the silent time after the end of a Modbus-SL packet communication.

Values from 0 to 10 ms (default setting: 5 ms)

Frames delay (ms)

Used to define the minimum silent time between the end of a received response and the beginning of a new request on the serial line

Values from 0 to 100 ms (default setting: 50 ms)

NOTE: The Frame Delay value needs to be aligned with the End Device Frame Delay. For example, if End Device Frame Delay equals 50 ms, then set 50 ms on Panel Server ). Data loss may occur if these values are not aligned.
Timeout (ms)

Used to define the timeout value after which a loss of communication is declared by the EcoStruxure Panel Server .

Values from 100 to 320,000 ms (default setting: 3,000 ms)

Termination resistor

Used to connect/disconnect the RS485 termination resistor embedded in the Panel Server to help prevent reflection. (Connect by default)

Serial line polarization

Used to enable/disable forcing the transmission line into a known state to help prevent invalid data bits (enabled by default). The transmission line into the RS485 port enters an indeterminate state when it is not being transmitted to. This indeterminate state causes the receivers to receive invalid data bits from the noise picked up on the cable.

Modbus Serial Server Configuration Settings

The following parameters are displayed only when the parameter of Modbus-SL mode is set to Server.

The following table describes the settings and where they are available.

Parameter Description EPC software Webpages
Baud rate (bits per sec) Used to set the transmission rate:
  • 1200

  • 2400

  • 4800

  • 9600

  • 19200

    (default setting)
  • 38400

  • 57600

  • 115200

Parity Used to define the parity bit of the transmitted bytes:
  • Odd

  • None

  • Even (default setting)

Number of bits 8 bits. Setting not editable.
Number of stop bits

Used to define the number of stop bits transmitted: 1 or 2 (default setting: 1)

Silent interval (ms)

Used to define the silent time after the end of a Modbus-SL packet communication.

Values from 0 to 10 ms (default setting: 5 ms)

Frames delay (ms)

Used to define the minimum silent time between the end of a received response and the beginning of a new request on the serial line

Values from 0 to 100 ms (default setting: 50 ms)

NOTE: The Frame Delay value needs to be aligned with the End Device Frame Delay. For example, if End Device Frame Delay equals 50 ms, then set 50 ms on Panel Server ). Data loss may occur if these values are not aligned.
Termination resistor

Used to connect/disconnect the RS485 termination resistor embedded in the Panel Server to help prevent reflection. (Connect by default)

Serial line polarization

Used to enable/disable forcing the transmission line into a known state to help prevent invalid data bits (enabled by default). The transmission line into the RS485 port enters an indeterminate state when it is not being transmitted to. This indeterminate state causes the receivers to receive invalid data bits from the noise picked up on the cable.

Message timeout (ms)

In Modbus network configuration, you can set the message timeout period for the Modbus-SL server.

Setting used to set the time-to-live of a Modbus request in the Panel Server . Any messages older than this setting will be dropped.

Values from 1000 to 32000 ms (default setting: 6000 ms)

The value that you set for the Modbus-SL server must meet both following conditions:

  • Be equal to the message timeout that is defined on the upstream Modbus client (SCADA or another Panel Server ).

  • Be higher than the timeout defined in the Panel Server Modbus client setting (Modbus TCP/IP and Modbus-SL).

Modbus Discovery Settings

The following table describes the settings and where they are available.

Parameter Description EPC software Webpages

Modbus serial discovery

Used to enter the list of Modbus addresses (1–254 ) for which the devices must be discovered.

* *

Discovered devices table

Displays information about each device discovered in the Modbus-SL network:

  • Picture
  • Device name
  • Server ID

Manual addition

Used to manually enter Modbus-SL devices:

  • Enter the physical server ID / Unit ID.
    A virtual server ID is assigned as part of the process.

  • Select the device type in the drop-down list.

*

Modbus-SL Reverse Mode

Panel Server Modbus serial port can be configured in reverse mode. The Modbus-SL reverse mode allows any Modbus client (for example, SCADA) connected to the RS485 port, to access data from Modbus TCP/IP devices connected to ETH1 and/or ETH2 Ethernet port, and from any associated wireless devices by means of the virtual Modbus ID of the wireless device, as shown on this diagram:

Modbus Serial Line network
Ethernet network

The Modbus-SL reverse mode can be set and monitored on the Panel Server webpages at Settings > Modbus Devices . In Modbus configuration change the Modbus mode from Client to Server.

I/O Smart Link Modbus Settings

If you configure or change the settings of a I/O Smart Link Modbus device by using EcoStruxure Power Commission software or through Smartlink SIB webpages, and then connect to Panel Server webpages, you must update the I/O Smart Link Modbus settings in the Panel Server webpage to synchronize the configuration.

It takes approximately one minute to get the I/O Smart Link Modbus configuration refreshed on the Panel Server webpages. You can navigate through the other Panel Server webpages during the synchronization.

You can not synchronize two I/O Smart Link Modbus devices at the same time.

When you have launched a synchronization, you cannot cancel the process.

I/O Smart Link Modbus Control

Output Control order can be sent through Panel Server webpages. This feature is used to control non-critical electrical loads.

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