Siemens step 7 write to string serial#

Sending data is equally simple - just grab the SEND_PTP function block from the instruction set. I would suggest calling this block using the 'FirstScan' bit (%M1.0) to make sure your settings are applied correctly every time the PLC starts. This will allow you to fully define your port configuration as needed. If you'd like to configure your port settings dynamically, no problem! There's a simple function block provided (on the instructions palette, located under Communication) called PORT_CFG. Again, you can do all of this directly from the Device Configuration view by scrolling through the properties for the module. The next step is to configure your port - set the baud rate, parity, stop bits, etc. Alternatively, there is a system constant tag created as well - you can find this under your Default Tag Table on the System Constants tab. You can view the port number by selecting the module in your device view - you're looking for the hardware identifier. Once you've added the module, a port identifier for the module will automatically be created. In Step 7, this is simple as opening up the device configuration device view and dragging the module to your PLC. The first step is to add the module itself to your device configuration.

I happened to have a CM 1241 RS485 module on hand, so that's what I used.

Siemens step 7 write to string serial#

The serial slave I was working with was incredibly flexible and accepts both RS-485 and RS-232. Siemens (and Step 7) makes setting up basic point-to-point communication incredibly simple. For the current application, I was writing a simple function block to broadcast data to a Red Lion serial slave display, but there are a variety of situations in which you may need to do to this, such as communicating with a VFD. While there are many people in this office who do this regularly with other Siemens PLCs, it was the first time for any of us on an S7-1200, so I thought I'd share my experience.įirst of all, if this is your first experience doing this, you're in luck. Today, I found myself setting up some simple point-to-point serial communication on a Siemens S7-1200.