I wanted to take on a special task at work by trying to build a control panel that would control the automation/manual action for a set of valves and a sensor. So i ordered a Siemens Logo! 12/24RC which came with "Soft Comfort" software. I have been working on it for awhile but haven't been able to grasp it.

So i come to the meat of my subject....i need to find a company or someone who is knowledgeable in this plc. I would like to eventually be able to understand how to program but right now i don't have the time. So all suggestions/tips/and advice would be much appreciated.*******Seattle area***

 

Hello Rhy,

I attached you a link with a description about Siemens Logo:
http://www.cameuk.com/camenew/tech-docs/12_URBACO/Install Guides/LOGO! - User's Guide.pdf

I recommend you not to wire directly to you PLC your inputs/outputs. You must build a "mini control panel", use relay for Digital Outputs..etc.

How many inputs/outputs you have? do you use analog inputs/outputs??
Even if Logo is cheap is more easy in the case of short circuit to replace a relay than changing the PLC or switching to another output available from your PLC.

About to your valves: the valve knows to stop at the end of close/open trip?? even if you keep voltage on the valve and the valve hit the end of the trip...the valve stops automatically or you must stop the voltage on the contactor. In that case I recommend you not to use relay because if your relay fails the PLC will not know to stop the voltage and the valve will break. You must wire direct to DO from PLC, without using other components.

If you have other question or you need software/help on your project you cold write to me.

best regards,
Alin

 

Thanks Alin

Here is a more detailed version of my scenario. My company (pretty small company) had a employee who made these control panels which allowed a operator to empty and fill a tank. The panel had a siemens logo plc and manual switches in it. The employee who use to work for us was fired and with him went the knowledge of how to program the plc.

So i have been kinda reverse engineering this panel, and the Logo (or perhaps any plc) has me tripped up. I know what the Logo is suppose to do....but i don't know how to make it do it.

Let me try and see if i can explain what what i need.

At work we have these tanks. A tank has a inlet about 3/4 the way up and a outlet and at the bottom . At the very top is a port in which a hose is connected to a air manifold which is has 2 "3-way" valves. 1 of the valves is connected to the "vacuum" side of a pump and the other valve is connected to the "pressure" side of the pump. The valves are connected by a "TEE" and the open port on the "TEE" goes to the tank. And the open ports on the "3-Way" valves vent out to atmosphere. About 2 inches below the inlet on the tank is a sensor that indicate when water has reached it.

So when the tank is in operation and the cycle begins the tank come under a vacuum which make it pull in water from its inlet. When the water level reaches the level sensor the air manifold needs to switch the valves so that the tank becomes pressurized and blows the water out the outlet. The whole operation can be done Automatically (with the plc) or manually by the use of switches.

As you know already the vacuum cycle of the tank is determined by the water reaching the level sensor...however the pressurized cycle of the tank is set by a countdown timer, and when the timer has counted down the tank will start a new cycle and be put under a vacuum. The countdown timer was adjustable by using the Logos push buttons.

I can wire the control panel with all the switches...but when it comes to programming that plc and telling it i want it to switch valves when the sensor is triggered and that i want a adjustable timer for the pressure side, and that i want to be able to use switches and not have the level sensor override my switches, just stumps me.

Well that's the gist of it...i wish i could send you a drawing to get your opinion but ill check out that website and see what i can find.

Rhy

 

Get a logo that's programed already. Copy the program on to a logo program card. You can now take this card and clone the program on to other logos.

I also suggest you copy the program on to a PC with the logo soft ware and learn it for troubleshooting and such. Most of it is in function block.

 

Hello Rhy,

Please send the drawing to [email protected]. I will guide you to write/copy the program to Logo.

best regards,
Alin

 

I can't take it from a logo which has the existing program on it because the old employee put a password on the program.

 

Ok Alin,

I really appreciate it. Ill scan everything i have and send it to you.

Have you experience using soft comfort software?

Rhy

 

Hello Rhy,

I tried to set up a Logo program between 1 master and 3 slaves

It don't work and I am blocked.

can you help me?

thx
franky de coninck

 

Hello Rhy,

I mainly program Rockwell PLCs and have no experience with Siemens. But I did find a Logo Soft tutorial on you tube. Man, I wish there was stuff out there like this when I first started out. Hope it helps. See the link below.