Configuring SIDirect DAServer to Communicate with S7 PLC Over TCP Connection
The SIDirect DAServer provides access to data within the Siemens S7 200, S7 300, and S7 400 PLC families through a standard EtherNet network interface card without requiring Siemens SimaticNet software. The SIDirect DAServer is capable of DDE, FastDDE, SuiteLink™, or OPC connections to Windows® client program such as an InTouch® application.
This Technote provides a step-by-step procedure of how to configure and use Wonderware's SIDirect DAServer with a S7 PLC (S7-400 PLC is being used in this technote) via DDE/SuiteLink protocol.
Before you continue, make sure the following requirements have been met:
- Read and follow the instructions in the SIDirect DAServer's readme file and related documents for System requirements, proper installation procedures, and supported Operating systems.
- Install the latest version of the SIDirect DAServer. If a previous version was installed, uninstall it using Add/Remove Programs in the Control Panel. This technote is written using SIDirect DAServer version 1.0.0.
- Install and configure TCP/IP network protocol and the network interface card (NIC)
so that it can communicate with the PLC via Ethernet.
- Make sure that you can "ping" the PLC successfully and receive valid replies from the PLC.
Configurating the SIDirect DAServer
- Start the SIDirect DAServer Manager by selecting Start/Programs on the taskbar.
- Navigate to the Wonderware folder that contains the System Management Console, then click System Management Console.
- From the ArchestrA System Management Console (SMC), find the SIDirect DAServer in the DAServer Manager tree. Under the local node the DAServer name is ArchestrA.DASSIDirect.1 (Figure 1 below).
Figure 1: DASSIDirect DAServer in the SMC
- Expand ArchestrA.DASSIDirect.1 and highlight Configuration.
The Global Parameters dialog box will appear as shown in Figure 2 (below):
Figure 2: DASSIDirect - Global Parameters
• Device Group Update Interval: Specifies the update interval of the default device group.
• Slow Poll Interval: Specifies the interval that the DAServer polls the field device after it goes into slow poll mode when connectivity problems occur. The DAServer will be governed by device group update intervals when the communication returns to normal.
• Transaction to Subscription Ratio: Transactions are poke/read messages from a DDE/SL/OPC client. Subscriptions are messages generated by items being on advise. Subscriptions are sent periodically at the Update Interval.
The Transaction to Subscription ratio defines the maximum number of transactions the DAServer sends before sending one subscription. It is the ratio of transaction to subscription messages when there are several transaction messages pending. The second half of the ratio is always 1. Therefore, the default ratio 2 means 2:1 transaction to subscription messages. The ratio ensures that a certain amount of subscription activity is guaranteed even in a transaction overloaded state.
For example if the ratio is set to 2 and there are 3 transaction messages and 2 subscription messages become due at the same time, the toolkit will send out 2 transaction messages, 1 subscription message, 1 transaction message and then 1 subscription message.
• Transaction Message Timeout: The timeout for transactions (read/write/refresh/property) per message. This timeout prevents a client from hanging in a transaction forever if for some reason the transaction messages are never scheduled until completion. It is the maximum amount of time between message updates within a transaction. The timeout has to be set in such a way that under no circumstances data acquisition on an individual message takes longer than this timeout.
• Server Protocol Timer: This option is disabled, since the SIDirect uses event driven protocol engine.
• Diagnostic Backlog Size: Specifies the maximum number of transactions shown in the Transactions diagnostic root.
• Poke Mode: The following modes are available:
- Control Mode preserves the poke order without folding.
- Transition Mode preserves the poke order with minimum folding by keeping the first, second and last poke values of an item.
- Optimization Mode does not preserve the poke order and has maximum folding by only poking the last value of an item.
• Case Sensitive: Controls how the DAServer scans item and device group names with respect to upper/lower case.
• Device Group Cache: This parameter is for future use.
• Simulation Mode: This parameter is is disabled for the SIDirect DAServer.
• System Items: This parameter controls whether the system items appear in the browse interface and if they are recognized as valid ItemIDs by the DAServer's data acquisition interfaces.
• Unique Device Groups: This parameter controls whether the device group names are checked for uniqueness across all device nodes of a DAServer.
Right-click the Configuration icon.
Select Add PortCpS7 Object from the sub-menu.
Right-click New_PortCp_000, and select Add S7Cp Object. The S7 CP parameter dialog window appears as shown in Figure 3 (below):
Figure 3: S7 CP Communication Parameters
• Network Address: Enter the IP address for the PLC. The S7 PLC used in the example of this technote has IP address of 192.168.10.41.
• Local TSAP: Specifies the local station's transport service access point. The first digit specifies the device, and the second digit should be zero (0). Recommended setting is 01.00.
• Remote TSAP: Specifies the PLC's transport service access point.
• Remote Rack No: Enter the decimal number for the Rack.
• Remote Slot No: Enter the decimal number for the Slot of the CPU.
The example in this technote uses the rack number 0 and the slot number 3 , where the S7-400 CPU is located. (The power supply takes up two slots, so the CPU is in slot 3.)
• Connection Resource: Select the Hex number for the Connection Resource from the drop-down menu.
- Select the Device Groups tab.
- Right-click on the white space in the Device Groups dialog box to add a device group ( similar to Topic Definition ) in the Device Groups dialog box as shown in Figure 4 (below):
Figure 4: Device Group Dialog Box
- Select, then right click the default Topic_0 to rename it to some meaningful name such as S7PLC as shown in Figure 5 (below):
Figure 5: S7PLC Device Group
- In the hierarchy tree on the left pane, right-click ArchestrA.DASSIDirect.1 and select Activate Server from the sub-menu to start the DAServer. The icon next to ArchestrA.DASSIDirect.1 will change from red to green as shown in Figure 6 (below):
Figure 6: SIDirect DAServer is Activated
Testing the DASSIDirect Server
The DASSIDirect Server is ready for use. We are now going to do a quick communications test to verify that we can establish the connection to the PLC.
- Click Start/Run and enter WWClient to start the Wonderware WWClient program.
- Select Connections/Create from the main menu. The Create Connection dialog box will appear.
- Enter appropriate information as shown in Figure 7 (below), where:
• Node: blank since the DASSIDirect and the WWClient are on the same computer. Otherwise, enter the computer name of the machine running the DAServer.
• Application: DASSIDirect, which is the application name of the SIDirect DAServer.
• Topic: S7PLC, which is the exact name of the new device group we just created in the DASSIDirect's device groups window.
• Connection Type: IOT which is the SuiteLink protocol used for this technote.
Figure 7: Create Connection Dialog Box
- Click Create, then Done.
The WWClient window should now appear similar to Figure 8 (below):
Figure 8: WWClient Showing Connection with the DASSIDirect
- Select Item from the main menu.
- Enter a known good PLC register address.
The following figures show an example of WWClient successfully advising item MB90 from the S7 PLC. Enter MB90 in the Item entry box. Click the AdviseEX button to register and advise the item. If the Ethernet connection to the PLC is good, you should see the value for the register MB90 as shown in Figures 9 and 10 (below):
Figure 9: Item
Figure 10: WWClient Displaying MB90 Values