1. Situation

A renewable energy plant gets two feed power requests, one from the grid operator and one from the direct marketer. The lower of each values must be used as feed power since the grid operator cannot transport a higher power or the direct marketer cannot sell a higher power. The grid operator issues a 104 protocol signal containing it’s feed power request. The direct marketer issues a Modbus signal containing it’s feed power request. The control of the renewable energy plant requests the feed power input as a Modbus signal. The two values need to be compared and the lower value (minimum) need to be transmitted to the renewable energy plant control via Modbus. Data transmission and computation takes place using an INSYS Smart Device (industrial router) located in the renewable energy plant using a secure VPN connection.

cg ids modbus 104 comparison

2. Solution

The icom Data Suite running on the INSYS Smart Device (industrial router) will act as a comparator of the Modbus and the 104 value and transmit the minimum of both values via Modbus. The icom Data Suite acts as a 104 server and enables the grid operator that acts as a 104 client to write the feed power request to a 104 protocol item. The icom Data Suite acts as a Modbus slave and enables the direct marketer that acts as a Modbus master to write the feed power request to a Modbus register. The two values will then be mapped to flags that can be compared by the icom Data Suite. The icom Data Suite will then compare both values and write the minimum of both values as a Modbus master into a Modbus register of the control of the renewable energy plant that acts as a Modbus slave.

It is prerequisite that you have access to the web interface of the icom Data Suite.
It is also prerequisite that the INSYS Smart Device (industrial router) is properly configured to establish the VPN connection to the grid operator and direct marketer as well as the Modbus connection to the control of the renewable energy plant.

2.1. Configuring the 104 Connection to the Grid Operator

  1. In the Data points → Flags menu, add a new flag () and configure it: [1]

    • Description: Feed power request - grid operator

    • Type: Unsigned integer

  2. Click on Save settings.

  3. In the Gateway → 104 server menu, add a new device () and edit it ():

    • Description: 104 gateway to grid operator

    • Port: 2404

    • Station address: 1

  4. Click on Save settings.

  5. In the Gateway → 104 server menu in the Items section, add a new item () and edit it (): [2]

    • Description: Feed power request from grid operator

    • Type: Mapping

    • Data point: Select above added flag

    • 104 type: Scaled value [3]

    • IOA: Enter the Information object address for the feed power request value [4]

  6. Click on Save settings.

2.2. Configuring the Modbus Connection to the Direct Marketer

  1. In the Data points → Flags menu, add a new flag () and configure it: [1]

    • Description: Feed power request - direct marketer

    • Type: Unsigned integer

  2. Click on Save settings.

  3. In the Gateway → Modbus menu, add a new device () and edit it ():

    • Description: Modbus gateway to direct marketer

    • Type: TCP

    • Port: 502

    • Slave address: Enter the slave address of the direct marketer [5]

    • Byte order: select as requested by the protocol

  4. Click on Save settings.

  5. In the Gateway → Modbus menu in the Mappings section, add a new mapping () and edit it (): [6]

    • Data point: Select above added flag

    • Type: Holding register [7]

    • Register: Enter the register address for the feed power request value [4]

    • Format: Unsigned integer 16 [8]

  6. Click on Save settings.

2.3. Configuring the Modbus Connection to the Renewable Energy Plant

  1. In the Data points → Modbus menu, add a new device () and edit it ():

    • Description: Modbus connection to renewable energy plant

    • Type: select the connection type TCP (TCP/IP) or RTU (serial) depending on the Modbus connection

    • Enter address and port for TCP or the serial parameters for RTU [9]

    • Polling interval: 5

    • Slave address: enter the Modbus slave address of the control of the renewable energy plant

    • Byte order: select as requested by the protocol

  2. Click on Save settings.

  3. In the Data points → Modbus menu in the Data points section, add a new data point () and edit it (): [10]

    • Description: Minimum feed power request

    • Type: Holding register [11]

    • Register: 1 [12]

    • Format: Unsigned integer 16 [13]

  4. Click on Save settings.

2.4. Configuring the Value Comparison

  1. In the ALU → Functions menu, add a new function () and edit it (): [14]

    • Description: Minimum feed power request

    • Type: Minimum

    • Capture value over time:

    • Input data points: Check the two flags added above containing the feed power requests

    • Additionally assign output value to: Check the Modbus data point added above [15]

  2. Click on Save settings.

  3. Activate the profile ().

3. Troubleshooting

  • View the Status → Current values page to check whether the flags receive the feed power request values. If the values are missing/incorrect there, check the configuration of the gateways in the icom Data Suite. If the correct values are displayed there, check the Modbus slave connection in the icom Data Suite.

  • View the appropriate logs in the Status → Log view page (also of the router) to locate possible problems.

4. Resources

The following ASCII configuration can be taken over using copy & paste. It must be observed that the individual parameters need to be adapted to the own application. Correct numbering must be observed for numbered parameters. Moreover, it must be observed that no existing parameters with the same number will be overwritten. A proper functionality can only be ensured if the opened profile has been created from default settings before.

ASCII configuration
datapoints.flags.flag.add
datapoints.flags.flag[1].active=1
datapoints.flags.flag[1].description=Feed power request - grid operator
datapoints.flags.flag[1].type=unsigned_int

gateway.104server.gateway.add
gateway.104server.gateway[1].active=1
gateway.104server.gateway[1].description=104 gateway to grid operator
gateway.104server.gateway[1].tcp_port=2404
gateway.104server.gateway[1].station_address=1

gateway.104server.gateway[1].item.add
gateway.104server.gateway[1].item[1].item_description=Feed power request from grid operator
gateway.104server.gateway[1].item[1].item_active=1
gateway.104server.gateway[1].item[1].item_type=mapping
gateway.104server.gateway[1].item[1].map_datapoint=flag1
gateway.104server.gateway[1].item[1].map_104type=mscaled
gateway.104server.gateway[1].item[1].map_104ioa=1

datapoints.flags.flag.add
datapoints.flags.flag[2].active=1
datapoints.flags.flag[2].description=Feed power request - direct marketer
datapoints.flags.flag[2].type=unsigned_int

gateway.modbus.gateway.add
gateway.modbus.gateway[1].active=1
gateway.modbus.gateway[1].description=Modbus gateway to direct marketer
gateway.modbus.gateway[1].type=tcp
gateway.modbus.gateway[1].tcp_port=502
gateway.modbus.gateway[1].serial_port=---
gateway.modbus.gateway[1].serial_speed=115200
gateway.modbus.gateway[1].serial_databits=8
gateway.modbus.gateway[1].serial_parity=par_none
gateway.modbus.gateway[1].serial_stopbits=1
gateway.modbus.gateway[1].slave_address=1
gateway.modbus.gateway[1].endianess=big_abcd

gateway.modbus.gateway[1].mapping.add
gateway.modbus.gateway[1].mapping[1].map_active=1
gateway.modbus.gateway[1].mapping[1].map_datapoint=flag2
gateway.modbus.gateway[1].mapping[1].map_type=holding_register
gateway.modbus.gateway[1].mapping[1].map_register=1
gateway.modbus.gateway[1].mapping[1].map_bit=
gateway.modbus.gateway[1].mapping[1].map_format=uint16

datapoints.modbus.device.add
datapoints.modbus.device[1].active=1
datapoints.modbus.device[1].description=Modbus connection to renewable energy plant
datapoints.modbus.device[1].type=tcp
datapoints.modbus.device[1].ip_address=192.168.101.13
datapoints.modbus.device[1].tcp_port=502
datapoints.modbus.device[1].serial_port=---
datapoints.modbus.device[1].serial_speed=115200
datapoints.modbus.device[1].serial_databits=8
datapoints.modbus.device[1].serial_parity=par_none
datapoints.modbus.device[1].serial_stopbits=1
datapoints.modbus.device[1].polling_interval=5
datapoints.modbus.device[1].slave_address=1
datapoints.modbus.device[1].endianess=big_abcd
datapoints.modbus.device[1].response_timeout=500
datapoints.modbus.device[1].byte_timeout=500
datapoints.modbus.device[1].read_delay=0

datapoints.modbus.device[1].datapoint.add
datapoints.modbus.device[1].datapoint[1].datapoint_active=1
datapoints.modbus.device[1].datapoint[1].datapoint_description=Minimum feed power request
datapoints.modbus.device[1].datapoint[1].datapoint_type=holding_register
datapoints.modbus.device[1].datapoint[1].datapoint_register=1
datapoints.modbus.device[1].datapoint[1].datapoint_bit=
datapoints.modbus.device[1].datapoint[1].datapoint_format=uint16

alu.functions.function.add
alu.functions.function[1].active=1
alu.functions.function[1].description=Minimum feed power request
alu.functions.function[1].type=min
alu.functions.function[1].datapoint=flag1,flag2
alu.functions.function[1].output_datapoints=mdbDp1
alu.functions.function[1].time_based=0

ASCII configuration download (right-click and save as)

Back to the Configuration Guides for the icom Data Suite

Back to overview

1. This creates a flag that will be used to compare the values.
2. This adds an item that can be written with the feed power request by the grid operator and will be mapped to a flag.
3. The type can be taken from the protocol description that should be provided by the grid operator.
4. This can also be taken from the protocol description.
5. Request this address from the direct marketer.
6. This adds a mapping that can be written with the feed power request by the direct marketer and will be mapped to a flag.
7. The type can be taken from the protocol description that should be provided by the direct marketer.
8. The value format can also be taken from the protocol description.
9. Serial parameters, addresses and protocol parameters are available from the manufacturer of the renewable energy plant.
10. This adds a data point that transmits the minimum feed power request to the control of the renewable energy plant.
11. The type can be taken from the protocol description that should be provided by the manufacturer of the renewable energy plant.
12. The register address can also be taken from the protocol description.
13. The value format can also be taken from the protocol description.
14. This adds a function that computes the minimum of the two values.
15. This assigns the minimum feed power request to the Modbus data point that will be written into the Modbus register of the control of the renewable energy plant.