s7/300/ hmi


Thread Starter


what is the cheapest and easiset way to interface a HMI to a siemens s7/300 processor. which has a dp port. must i use pro-tools and a siemens OP?


Andrew Hawdon

The easiest way is to use Siemens Protool and a Siemens OP. It is probabily best to use the MPI interface that comes on all S7300 CPU'S. If you go for DP you will need a DP card in the PLC rack or an S73XX-2DP PLC. You can use a range of third party HMI's but in most cases you will still have to buy the configuration software. The other thing to watch for is the fact that some do not support MPI or DP directly and require a converter between the OP and PLC.


Zan Von Flue

my personal experience is Siemens is maybe not the cheapest OP or Protool software, however the Siemens OP and Protools works 100% with your project. Plus has alot of other functions other companies don't have.
Stay with the MPI connection.

It depends on what you consider cheap and easy. What size are you looking for, what kind of panel, text, graphics, touch or non-touch. There are some panels out there that can be less expensive than Siemens and if you are looking for cheap that is what you will get. If you are looking for easy you won't find anything easier than a Siemens panel connecting to a Siemens
PLC. When you install ProTool in the integrated mode (integrated with Step7 - the PLC programming package) your data base of symbols now becomes
available for use in ProTool. If you use a third party HMI than that feature is not available. I do not know about you, but I hate typing symbols twice. In a large project, say 250 tags or more, this can be very time consuming. The other feature that you will get when you stick with one
vendor for your PLC and HMI is common support. If you have a problem and you do not know if it is the HMI or the PLC who do you call if you use
separate vendors. One other thing that you do not get when you use a third party vendor is the feature called S7 alarms. These are alarms that you configure in the PLC that are time stamped and are available to ProTool. Normally you would configure all of your alarms in your HMI and poll bits in the PLC. When the alarm is true then your HMI will display it. With the S7 alarm feature there is no need to do all that tedious alarm configuring in the HMI and the fact that the alarms are configured in the PLC there is no
need for the HMI to poll the PLC, thus freeing up your DP network for more important tasks like I/O update. I could go on and on but from the sound of your question it looks like you have already discounted the Siemens HMI out. Yes, ProTool can be a little difficult for someone that has used other packages. That is usually the norm for German products, but once you really learn them you find that the features and benefits out way the difficult learning curve. You will find that you can do far more with them than any of the so called cheap and easy products.

Ron Powers
SR. Product Specialist-HMI/IPC
Siemens Energy & Automation-Solutions Business Unit
Validation Center
5300 Triangle Pkwy
Norcross, GA. 30092
[email protected]