Connecting to the S7 PLC

The Programming Cables

There are three major types of programming cables:

1. The CP5512 card in a PCMCIA slot.

2. The PC Adapter using a serial or USB connection

3. An Ethernet cable

The CP5512 card and the PC Adapter can communicate on either an MPI or PROFIBUS port. Note that PROFIBUS is labeled as DP on the Siemens connection ports. These cables can piggyback on existing connectors. Be aware that the PC Adapter draws its power to work from the connection port so check the power LED for proper operation. The CP5512 card draws its power from the computer.

For Ethernet (TCP/IP) use a standard Ethernet cable from the computer to a CPU with an Ethernet port, a CP 343/443 module or a network switch all ready attached to the PLC network.

Checking Communications

With the programming cable plugged in, you can check for proper operation by clicking on the Accessible Nodes icon.

If communications are successful, you'll see a window pop up similar to the one below. If so, then close the Accessible Nodes window and proceed to the download or upload section.

If communication fails then you will receive a message like below.

This indicates that the cable is not in the right computer port or the cable is not plugged in properly.

Setting the PG/PC Interface

In order to start communication to the PLC you will need to match the "PG Interface" setting with the programming cable and protocol. To do this, select the menu Options > Set PG/PC Interface.

The following dialog box will open up displaying all the different interfaces (i.e. communication drivers).

Each cable has its own interface. For Ethernet select the TCP/IP interface for your computers network card. Be careful not to select your wireless Ethernet connection.

To get it working quickly it is best to select the interface with the Auto designation. This will discover working settings and use them automatically.

For the PC Adapter click on the Properties button and make sure the Station Parameters Address is a unique network address. It should not conflict with existing PLC and slave devices on the network. Also, check under the Local Connection tab and make sure connection selection matches the port the cable is connected into.

Once the proper interface is selected and the properties are set then click OK and use the Accessible Nodes window to check for successful communications. It should work. If not double-check the connection and cable. With the CP5512 and PC Adapter cables, you should use the MPI port, as this is the default connection for Siemens.

If this doesn't work then I don't know what to tell you.