Selecting and Changing Parameters

Selecting the Correct Interface Parameter Set and Setting It Up

When you have reached the Setting the PG/PC Interface dialog box, be sure that “Micro/WIN” appears in the Access Point of Application list box (see Figure 4). The Setting the PG/PC Interface box is common to several different applications, such as STEP 7 and WinCC, so you may need to tell the program the application for which you are setting parameters.

When you have selected “Micro/WIN” and have installed your hardware, you need to set the actual properties for communicating with your hardware. The first step is to determine the protocol that you want to use on your network. You should use PPI protocol for all of your CPUs.

When you have decided what protocol you want to use, you can choose the correct setup from the Interface Parameter set used list box in the Setting the PG/PC Interface dialog box. This box lists each hardware type that you have installed, along with the protocol type in parentheses. For example, a simple setup might require you to use the PC/PPI cable to communicate with a CPU 222. In this case, you select “PC/PPI cable(PPI).”

After you have selected the correct interface parameter set, you must set up the individual parameters for the current configuration. Click the “Properties...” button in the Setting the PG/PC Interface dialog box. This action takes you to one of several possible dialog boxes, depending on the parameter set that you selected (see Figure 7). The sections that follow describe each of these dialog boxes in detail.

In summary, to select an interface parameter set, follow these steps:

1.In the Setting the PG/PC Interface dialog box (see Figure 4), select “Micro/WIN” in the Access Point of Application list box in the Access Path tab.

2.Ensure that your hardware is installed.

3.Determine the protocol that you want to use. You should use PPI protocol for all of your CPUs.

4.Select the correct setup from the Interface Parameter Set Used list box in the Setting the PG/PC Interface dialog box.

5.Click the “Properties...” button in the Setting the PG/PC Interface dialog box.

From this point, you make selections according to the parameter set that you chose.

Setting Up the PC/PPI Cable (PPI) Parameters

From the Setting the PG/PC Interface dialog box, if you are using the PC/PPI cable and you click the “Properties...” button, the properties sheet appears for PC/PPI cable (PPI). See Figure 7.

STEP 7-Micro/WIN 32 defaults to multiple-master PPI protocol when communicating to S7-200 CPUs. This protocol allows STEP 7-Micro/WIN 32 to co-exist with other master devices (TD 200s and operator panels) on a network. This mode is enabled by checking the “Multiple Master Network” check box on the PC/PPI Cable Properties dialog in the PG/PC Interface. Windows NT 4.0 does not support the multiple-master option.

STEP 7-Micro/WIN 32 also supports a single-master PPI protocol. When using the single-master protocol, STEP 7-Micro/WIN 32 assumes that it is the only master on the network and does not cooperate to share the network with other masters. Single-master protocol should be used when transmitting over modems or over very noisy networks. The single-master mode is selected by clearing the “Multiple Master Network” check box on the PC/PPI Cable Properties dialog box in the PG/PC Interface.

Follow these steps to set up the PPI parameters:

1.In the PPI tab, in the Station Parameters area, select a number in the Address box. This number indicates where you want STEP 7-Micro/WIN 32 to reside on the programmable controller network. The default station address for the personal computer on which you are running STEP 7-Micro/WIN 32 is station address 0. The default station address for the first PLC on your network is station address 2. Each device (PC, PLC, etc.) on your network must have a unique station address; do not assign the same address to multiple devices.

2.Select a value in the Timeout box. This value represents the length of time that you want the communications drivers to spend to attempt to establish connections. The default value should be sufficient.

3.Determine whether you want STEP 7-Micro/WIN 32 to participate on a network that has multiple masters. You can leave the check mark in the Multiple Master Network box, unless you are using a modem or Windows NT 4.0. In that case, the box cannot be checked because STEP 7-Micro/WIN 32 does not support that functionality.

4.Set the transmission rate at which you want STEP 7-Micro/WIN 32 to communicate over the network. The PPI cable supports 9.6 kbaud and 19.2 kbaud.

5.Select the highest station address. This is the address where STEP 7-Micro/WIN 32 stops looking for other masters on the network.

Figure 7 Properties - PCPPI Cable (PPI) Dialog, PPI Tab

6.Click the Local Connection tab. See Figure 8.

7.In the Local Connection tab, select the COM port to which your PC/PPI cable is connected. If you are using a modem, select the COM port to which the modem is connected and select the Use Modem check box.

8.Click the “OK” button to exit the Setting the PG/PC Interface dialog.

Figure 8 Properties - PCPPI Cable (PPI) Dialog, Local Connection Tab

Configurations Using a PC with an MPI or CP Card: Multiple-Master Network

Many configurations are possible when you use a multipoint interface card or communications processor card. Either card provides a single RS-485 port for connection to the network using an MPI cable. You can have a station running the STEP 7-Micro/WIN 32 programming software (PC with MPI or CP card, or a SIMATIC programming device) connected to a network that includes several master devices. (This is also true of the PC/PPI cable if you have enabled multiple masters.) These master devices include operator panels and text displays (TD 200 units). Figure 9 shows a configuration with two TD 200 units added to the network.

Note:

If you are using the PPI parameter set, STEP 7-Micro/WIN 32 does not support two different applications running on the same MPI or CP card at the same time. Close the other application before connecting STEP 7-Micro/WIN 32 to the network through the MPI or CP card.

In this configuration, the communication possibilities are listed below:

·STEP 7-Micro/WIN 32 (on station 0) can be monitoring the status on programming station 2, while the TD 200 units (stations 5 and 1) communicate with the CPU 224 modules (stations 3 and 4, respectively).

·Both CPU 224 modules can be enabled to send messages by using network instructions (NETR and NETW).

·Station 3 can read data from and write data to station 2 (CPU 222) and station 4 (CPU 224).

·Station 4 can read data from and write data to station 2 (CPU 222) and station 3 (CPU 224).

It is possible to connect many master and slave stations to the same network. However, the performance of the network can be adversely affected as more stations are added.

Figure 9 Using an MPI or CP Card to Communicate with S7-200 CPUs

Setting Up the CP or MPI Card (PPI) Parameters

This section explains how to set up the PPI parameters for the following hardware:

·CP 5511

·CP 5611

·MPI

From the Setting the PG/PC Interface dialog box, if you are using any of the MPI or CP cards listed above along with the PPI protocol, and you click the “Properties...” button, the properties sheet appears for XXX Card (PPI), where “XXX” stands for the type of card you installed, for example, MPI-ISA. See Figure 10.

Note:

Use the MPI protocol when you are communicating to an S7-200 CPU 215, port 1.

Follow these steps to set up PPI parameters:

1.In the PPI tab, select a number in the Address box. This number indicates where you want STEP 7-Micro/WIN 32 to reside on the programmable controller network.

2.Select a value in the Timeout box. This value represents the length of time that you want the communications drivers to spend to attempt to establish connections. The default value should be sufficient.

3.Set the transmission rate at which you want STEP 7-Micro/WIN 32 to communicate over the network.

4.Select the highest station address. This is the address where STEP 7-Micro/WIN 32 stops looking for other masters on the network.

5.Click the “OK” button to exit the Setting the PG/PC Interface dialog box.

Figure 10 MPI-ISA Card (PPI) Properties Sheet

See Also:

Communications Timeout