Entry type: FAQ, Entry ID: 19081112, Entry date: 06/21/2004

Reading the input data of a DP slave configured by a different DP master

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Can a DP master read the input data of a DP slave configured by a different DP master?

Yes, by configuring direct data exchange a DP master can read the input data of a DP slave not operated by that DP master. In this case both DP masters have to be available as a multi-master system in a physical PROFIBUS DP subnetwork.

For direct data exchange both DP masters must support "send and receive capability for direct data exchange" and the DP slave must support "send capability for direct data exchange".

You can determine these properties for both the DP master and the DP slave from the module data displayed in the Hardware Catalog window in STEP 7 Hardware Configuration (HW Config).

Fig. 1: Send and receive capability for direct data exchange in the DP master

Fig. 2: Send capability for direct data exchange in the DP slave

Sample products that support direct data exchange:

DP Slave

  • ET200 L
    6ES7 131-1EH00-0XB0 - electronic module DI 16 x AC 120V
    6ES7 133-1EH00-0XB0 - electronic module DI8/DO8 x AC120V
    6ES7 133-1JH00-0XB0 - electronic module DI8/RO8 x AC120V
    6ES7 133-1BL01-0XB0 - ET 200L 16DI/16DO DC 24V/0.5A

  • ET200 M
    6ES7 153-1AA03-0XB0 - IM 153-1, distributed, PROFIBUS-DP
    6ES7 153-1AA83-0XB0 - IM 153-1, distributed, PROFIBUS-DP

  • ET200 S
    6ES7 151-1CA00-0AB0 - ET 200S interface module IM151-1 BASIC
    6ES7 151-1AB02-0AB0 - ET 200S interface module IM151-1 FO STANDARD
    6ES7 151-1BA00-0AB0 - ET 200S interface module IM151-1 High Feature
    6ES7 151-1AA03-0AB0 - ET 200S interface module IM151-1 STANDARD

  • ET200 X
    6ES7 147-1AA01-0XB0 - ET200X: basis module BM147/CPU
    6ES7 147-1AA10-0XB0 - ET 200X: basis module BM147-1 CPU
    6ES7 141-1BF01-0XB0 - ET200X: basis module BM141, 8DI
    6ES7 141-1BF01-0AB0 - ET 200X: BM141 - ECOFAST RS485 8DI

DP Master

  • C7
    6ES7 626-2DG04-0AE3 - SIMATIC C7-626/P DP, complete device
    6ES7 633-2BF02-0AE3 - SIMATIC C7-633 DP, complete device
    6ES7 634-2BF02-0AE3 - SIMATIC C7-634 DP, complete device
    6ES7 635-2EC01-0AE3 - SIMATIC C7-635 Keys, complete device
    6ES7 635-2EB01-0AE3 - SIMATIC C7-635 Touch
    6ES7 636-2EC00-0AE3 - SIMATIC C7-636 Keys, complete device

  • S7-300
    6ES7 313-6CE01-0AB0 - CPU313C-2 DP,32KB,16DI / 16DO;DP-SS M/S
    6ES7 314-6CF01-0AB0 - CPU314C-2 DP,48KB,24DI / 16DO/ 4AI / 2AO, DP-SS M/S
    6ES7 315-2AF03-0AB0 - CPU 315-2 DP, 64 kB, 0.3 ms/kAW
    6ES7 315-2AG10-0AB0 - CPU 315-2DP, 128 kB, 0.1 ms/kAW
    6ES7 315-6FF01-0AB0 - CPU 315F
    6ES7 316-2AG00-0AB0 - CPU 316-2DP, 128kB, 0.3 ms/kAW
    6ES7 317-2EJ10-0AB0 - CPU 317-2 PN/DP, 512 kB, 0.05 ms/kAW
    6ES7 317-6FF00-0AB0 - CPU 317F-2DP, 512 kB, 0.1 ms/kAW
    6ES7 318-2AJ00-0AB0 - CPU 318-2, 512 kB, 0.1ms/kAW

  • S7-400
    6ES7 412-1XF03-0AB0 - CPU 412-1, 96 kB, 0.2ms/kAW
    6ES7 412-2XG00-0AB0 - CPU 412-2, 144 kB, 0.2ms/kAW
    6ES7 414-2XG03-0AB0 - CPU 414-2, 256 kB, 0.1ms/kAW
    6ES7 414-3XJ00-0AB0 - CPU 414-3, 768 kB, 0.1ms/kAW
    6ES7 416-2XK02-0AB0 - CPU 416-2, 1.6 MB, 0.08ms/kAW
    6ES7 416-3XL00-0AB0 - CPU 416-3, 3.2 MB, 0.08ms/kAW
    6ES7 416-2FK02-0AB0 - CPU 416F-2, 1.6 MB, 0.08ms/kAW
    6ES7 417-4XL00-0AB0 - CPU 417-4, 4 MB

  • ET200 S-CPU
    6ES7 151-7AA10-0AB0 - ET 200S IM 151 CPU, 48kByte

Configuring direct data exchange
The direct data exchange functionality is configured in the configuration of the DP master that is "listening in". In the configuration of the DP master that is operating the DP slave you simply have to set up normal master-slave communication.

In the sample project enclosed an ET 200S station (DP slave) is operated by a CPU 318-2 (DP master). A CPU 416-2 DP located on the same PROFIBUS DP network reads the data of the ET 200S input modules via direct data exchange.

You must set the following when configuring the CPU 416-2DP the DP master that is listening in:

  • Open the Properties of the DP interface and select the Configuration tab. Here you insert a new line that is parameterized for the DX mode (for direct data exchange).

Fig. 3: Configuration of CPU 416-2 DP

  • Edit the configuration of the DX by entering the DP address of the DP slave and the input address of the relevant data.

Fig. 4: Configuration - direct data exchange

Fig. 5: Sample project configuration ( 21 KB )  

Sample project:
Copy the "Direct_data_exchange.exe" file into a separate directory and then start the file with a double-click. The project created in STEP 7 V5.2 SP1 is now unpacked automatically with all the associated subdirectories. Then you can use the SIMATIC Manager to open and process the unpacked project.

Direct_data_exchange.exe ( 192 KB )