Read performance MindConnect Elements

All MindConnect Elements have a clear limitation on soft limits(unmonitored number of data points and data connections). The only fixed limit is 1050 data points. Within the soft limits, you can configure data connections and data points without reaching the limits. For 250 datapoints read per second, the upload bandwidth should be at least 0.5 MB/s.

The following describes how to proceed if you want to exceed these limits.

Tested MindConnect limits

MindConnect Nano

MindConnect IOT2040

Max mount of data points can be configured (Fix)

1050

1050

Data points OPC UA / S7 / Modbus TCP (read per second)

250

30

Connections to data providers

30

5

String data points

10

3

Data points - Modbus RTU RS485 / RS422 - 9,6 kBd

20

15

Data points - Modbus RTU RS485 / RS422 - 19,2 kBd

35

20

Data points - Modbus RTU RS485 / RS422 - >= 38,4 kBd

80

30

Data points - Modbus RTU RS232 - 57,6 kBd

40

30

Adaptions of the limits

Subsequently listed are the parameters the influence the read performance of a MindConnect Element. By varying one of these parameters all others will be affected as well. These are the variables:

  • Performance of MindConnect hardware

  • Number of connections to data providers

  • Type of connection to providers (S7 / OPC UA / Modbus / ...)

  • Amount of data points per second

  • Type of data points (String or no string)

  • Performance of data provider (PLC, OPC Server)

NOTE

Reading data from a data provider will always cause an effect on it. The performance of the data provider (PLC / OPC Server / Modbus) is one of the most important limiting factors. If more devices (e.g. OPC server, HMIs, SCADA systems,...) are connected to this data provider (e.g. PLC) the reading cycle can rise.

Example calculations (MindConnect Nano)

  • It can be possible to read 300 data points per second out of a PLC. This is possible if the PLC is powerful and just one data provider is used.

  • It can be possible to read 1000 data points out of 30 data providers if the reading cycle will be switched to 4sec.

  • It can be possible to read out of 35 data providers if you just read 200 data points per second.

NOTE

To make sure a configuration works for your setup it needs to be monitored over a longer period of time.

System Test results

The following tables show how long it takes to read a data item from one of the devices. These are not fixed values but an indication of how the devices would react.

MindConnect NANO

Type

MS per data point read

Min

Mid

Max

S7 300

1,13

1,74

3,08

S7 1500

0,37

1,60

3,89

S7 1200

3,50

5,18

7,50

S7 ET200S CPU

0,89

2,09

3,71

OPC UA @ PC1)

2,38

6,64

8,53

OPC UA@ PLC

2,66

3,27

4,69

1) OPC UA @ PC always depends on the hardware.

  • Read of a string data point you have to multiply the time with 2,5 per data point 

  • All devices are around 75% full

MindConnect IOT2040

Type

MS per data point read

Min

Mid

Max

S7 300

2,10

4,28

6,61

S7 1500

3,73

4,54

5,22

S7 1200

6,29

6,72

7,11

S7 ET200S CPU

1,92

5,01

8,33

OPC UA @ PC

OPC UA@ PLC

4,42

5,50

7,66

  • Read of a string data point you have to multiply the time with 2,5 per data point 

  • All devices are around 75% full