Sunday, September 25, 2011

Solve CP1H R88D Servo Motor Controller

I work around a CP1H R88D servo with a pulse output 0 problem. All power settings are standard, except for the electronic gear ratio. The example is the Handbook of 2000 pulses per revolution motor set.
Fine adjustment of the drive car (one horizontal spindle).

I have the move to Omron (power) function block in the CP1H.
The distance between the CP1H and the servo is about 6 m (2 m). The drive is a Panasonic with brake and encoder (not absolute).


Two cases:
1. 2000 pulses is not a revolution engine, only about 3 / 4 2000 pulses also not equal to 2000 forward pulse times (by a significant amount).
2. The highest speed I can use and still move the actuator 100, although I keep hearing that the CP1H is capable of more. The CP1H seems not the problem. When ordered with a speed of more than 100, the power simply ignore the incoming pulse.

I’ve been through all CP1H/R88D manual and found no answers. Has anyone successfully ran a similar sytem? Anyone have a hint of things to look for?
The manuals never a PNP output to the PLC station in pulse mode. It seems that the manuals are to be desired. I found three departments, which called into question. Well, I’m looking forward to implement the same system with an absolute encoder - should be a breeze - right!

Saturday, September 10, 2011

Monitoring memory space in the PLC.

Often used in the PLC to consider that choosing which version to use the CPU will have enough space to run the program. The count is difficult enough to evaluate. Because the function of machines, each machine has a different way of thinking is difficult and complex simplicity. And do not depend on the number of I / O.
So if you find ways to estimate a cursory I can do it without writing a program in advance because the CX-Programmer. Can be simulated. (Must be a joint program with the CX-Simulator).

Steps to use.

1. When writing a program so close to actually work. Is enough to see the capacity of content from programs like the CX-Programmer Tools by going to the Cross-Reference Report or press Alt + x.



2. Press the button Generate.

Total UM status means that all memory of this PLC model.
Free UM status means that the available memory remaining space to tell the normal PLC programming in units of step.

3. Commands each command of the PLC. To use the same memory. Depending on the complexity of the computation of new CPU can see that each step of the orders at the end of Part Programming Manual.


4. Students. Cross-Reference Report in addition to more memory space, the rest of the PLC can also be sure that nothing of the PLC variable that is already taken some Used many times. This would be ideal to modify or add applications. Which can be selected Report type: Usage overview (which is pretty. It shows only the active variables) Memory area: Choose the type of variables to display.

5. And then press the Generate button, the program displays a report describing the use of memory out.

Monday, September 5, 2011

History of PLCs

Today i have article that story in PLCs,Twenty-five years I was in my last year with Allen-Bradley PLC and a specialist and educator. I grew up with the PLC in 1774, the PMC. What a trip through the PLC-2, PLC 3, PLC 5, computer-based programming instead of a luggable terminal and a 10 MB hard disk for the PLC-3 GA module for remote data collection and programming remotely through the RM modules.

A laptop for programming (Data General) was more than $ 8,000. Hard drive space is outrageous expensive, and Windows will not be used. PCs were ahead, and programmers learned useful DOS software.
From 1977 to 1985 there was an enormous growth pattern that most had not imagined. Remote I / O, HMI, SCADA, and similarly, the PLC to the DCS world compromise. Servo Control was also available. Special keyboards set them up.
Bit-flipping was an art.

We had to do in ASCII module interfaces, and network modules with interfaces for mini-computers like the DEC VAX and PDP-11.

Some applications were too fast for the PLC, but not much. Everything was a good deal for the PLC and the companies and individuals.

In 1986 I founded my own company and am involved with the newfangled software arena. Life changes decision proved quite good.

ICOM, Tele-thinking, tender gray, Taylor et al. made DOS-based PC programming software. Moved to PC-based HMI and ARCnet came to town.

But what really changed since 1985? It depends on who you ask. Marketing vs Engineering is the battlefield, as hardware costs have fallen to the point of goods.

Let me table for the next month to develop a perspective on where we are and where we come from.

Applications that make use of automation changed, but some are not. The reasons for the use of automation, more enterprise-centric. This wish it was in 1985-it just was not easy to implement.

“Real time” a new meaning, so that access to data is crucial. It was, but the preservation of the data was primitive. OEMs developing and producing their own interfaces for the collection of data for customers. We just have easy access to such data today.


Electrician to resolve successfully the systems of fixed terminals. The documentation was found on the printed scale. Difficult to navigate, but they were successful.

Encoders, converters, control circuits and more linked (then and today) with special I / O. Today, however, there are I / O buses, remote I / O of something. Instead of treating a PLC data table for hiking or quantitative information, you get the data from the device. But the data is similar, yes?

At the risk has changed, old, I do not think much. ControlLogix is ​​no different than the PLC-3 from 1980. You can scan multiple cards to support redundancy, the use of special communication card, data collection and other languages. It is a remote I / O and remote programming possible in both.

Applications are available for client / server environments. Mainly based on UNIX, but they worked.

Then something really monumental happened changed the rules changed, the development cycle, and changed the operative work. This cycle / career change made changes, what we have today. We had the goods but few were in force.

The shift was monumental software. Windows 3.0, NT and IBM OS / 2 Presentation Manager creates a free-for-all. A small company called Wonderware HMI took over the company. Because it was so easy, PLC were targeted. Ethernet landed in the workplace, and ensure that each Ethernet PLC had to speak.

New and improved technology may not necessarily be a different function. get from 1985 to 2010 Oldsmobile Porsche both what you want. We want to buy different things with the data. This requires a number of different “things” and it’s slow, painful and not to the order indicated that to change much advertising.