advantages of s7 200 over logo! <--- newbie alert

[kk4life]

hey, i was wondering in what ways is s7 200 better than logo. i mean other than having more expansion modules and the s7 200 can be used on a large scale. if u could tell me the pros and cons of s7 200 and logo, tht will be great. thanks in advance

[Crossbow]

S7-200 is a PLC. As such, it has more capabilities, including floating point math. Logo is a smart relay. While Logo does have a basic programming language, it is NOT a PLC. It's designed for simple timer/counter/time clock applications, not for high end control systems. S7-200 adds data logging, high resolution analog, modem and network capabilities, and more.

[ramaslabas]

And prog scan time for LOGO! is XXXms. I already met aplications when system does not work because did not catch signals from sensors.

[Crossbow]

Logo is not intended for high speed applications, just for basic control where in the past relays and timers or counters would have been used. It's not a PLC, and as such, isn't designed to be fast. But then some people think since it's in their automation catalog it must be some really cool new low end PLC.

[Gazzr]

I have programmed a few logo's for small tasks and have just got a S7-200 for a slightly more advanced project as this was the natural next step in the Siemens range. (That and the fact that I wanted to get my teeth into one) It is quite a huge difference. Not quite so user friendly, but i think I am getting there (Slowly). The Logo's are great, and I believe they are a PLC, albeit a very low end one. The one thing i "miss" or have not yet found is the ability to do a simulation with the software for the S7-200. Instead the program has to be written to the device and then go online with it and use an input simulator. (Although somebody may reply to this and tell me how wrong I am) Anyway, back to your question of advantages of S7-200 over Logo. The reason I went for one was because of the Logo's lack of data handling capabilities. And now I have these capabilities...... I'm lost. But learning by the day.

[Crossbow]

Even Siemens calls Logo a 'smart relay'. It's not designed to be a PLC. As for the software, no simulation capabilities in Step 7 MicroWin. Step 7 is a real PLC programming software, and as such has many more features and options than LogoSoft. This would make it far more complex for a new user to understand. But Step 7 MicroWin does have wizards built in to configure most special modules. And the ladder logic programming is standard IEC 61131-3 style.

[kk4life]

Thanks guys. Appreciate the input. I have to port basic functions from LOGO to S7 200 as an introduction guide. LOGO was easy to create programs as compared to S7 200. The LAD and FBD in S7 200 is different. I will have to do read through the S7 200 manual on creating programs.