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Saturday, May 7, 2016

CNC PLC Programming

CNC PLC Programming:

CNC PLC Controls Troubleshooting

CNC PLC programming may be done within the CNC controller/CNC operator control panel or as in most cases there is a separate PLC for CNC machine. In the latter, maintenance would connect directly with the PLC and use that particular PLC vendor's software to access the CNC PLC programming.

This post and article referenced is about troubleshooting the CNC PLC control, and who can do what. Typically the CNC machine operator troubleshooting task is limited to responding to alarms on CNC control panel and visual inspections. Then if CNC operator can not resolve issue, maintenance is called and they will often use PLC ladder logic to speed more technical troubleshooting process as shown in the CNC PLC Control troubleshooting flowchart. The multi-meter is another supporting tool maintenance uses once the PLC ladder logic has quickly narrowed down the area of the system to test.

CNC PLC Controls Troubleshooting

The PLC programming for CNC machine is commonly simple as the PLC typically only controls peripheral devices that support the CNC controller. Like this CNC PLC Control troubleshooting flowchart article example, the CNC door closed confirmation signal is detected by PLC and then communicated to CNC. The PLC may control and/or monitor other supporting device too like the coolant pump, the chip conveyor, indicator lights, air solenoid, etc. That article is a great example of use of PLC in CNC machines and sheds some additional light on difference between PLC and CNC machines. 

There are exceptions to every rule, so in some more rare CNC designs, things can get more complicated than described above. Instead of the PLC communicating to the CNC (industrial computer), the PLC could be emulated by the CNC controller itself. (Just like a PAC does, as a PAC is an industrial computer emulating a PLC.) Also if the CNC is having motor drive issues it can get more complex. Some CNCs communicate axis speeds and feeds to PLC which then in turn sends data to motor drives, some CNCs send data directly to drives and only use PLC for peripheral device.

Increasing CNC operator maintenance level training is a growing trend to help reduce maintenance workload so maintenance can better  keep up with the ever growing technological advances in the industry and to reduce downtime waiting on maintenance to arrive. That possibility is explored in article linked to above using the CNC PLC Control troubleshooting flowchart with door closed signal example, If PLC LEDs are made visible to CNC operator, and they receive basic PLC training, they can often narrow down problem even further saving maintenance time. (... without using a computer or multi-meter) Often figuring out on their own and not needing maintenance, thus reducing downtime.

What are your thoughts?

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Tuesday, April 26, 2016

PLC Communication Protocols

PLC Communication Protocols:

(Fieldbus Communication Protocols)

There are a lot of PLC Communication Protocols out there, especially when you consider the evolution of the PLC to the industrial computer (PAC)  and  Ethernet. But today lets explorer some of the most popular Fieldbus Protocols.

From Foundation Fieldbus protocol to ProiBus, to HART and even ASibus protocol. the above video introduces them all, the Online Fieldbus Training course dives into the details of each. They are often used PLCs to DCS, most common in process industries, but in manufacturing too. Even in building automation systems (BAS).

Because of Fieldbus and other communication protocols and technology, process controllers no longer need to be located close to the process. The analog sensors and actuators can communicate with PLC/PAC over greater distances than if the field device was just hard wired into the PLC analog input or output card.

In order to understand the workings of a Fieldbus based system, the Fieldbus course below first starts with Fieldbus basics teaching you about the various types of signals uses in an automation system. From the 4 to 20ma current loop, to digital signals like Manchester encoding. Bit oriented buses like ASi are covered, byte oriented buses like CAN and DeviceNet, and message oriented buses like Foundation Fieldbus and ProfiBus are discussed.

You'll learn about the various topologies ...master, slave, star, ring, FISCO, etc. Get familiar with DCS architecture, power supplies, troubleshooting, applying Fieldbus in hazardous areas. Even a walk through of a Fieldbus project, from beginning to end! And so much more in this huge course coverall the popular PLC communication protocols.

Hope you like and share the Fieldbus Technology Tutorial video above. Thanks

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Friday, April 1, 2016

Industrial Process Control | Pressure Transmitters

Industrial Process Control

>> Pressure Transmitters |  Differential Pressure Transmitters

Differential Pressure Transmitters
What is a Differential Pressure Transmitters? A sensor to detect and measure process pressure.

The differential pressure transmitters is a sensing element connected by pipe work and flexes in proportion to the pressure. The resulting distortion produces an electric signal that is amplified and converted to a value on a read-out. The process side of the sensor sees the pressure to be measured while the other side is connected to a reference pressure. The reference pressure can be full vacuum, atmospheric pressure or another process pressure. Also  by connecting the differential pressure transmitters across an orifice plate in a pipeline, the pressure difference across the orifice can be put into a formula to calculate flow.

To prevent chemicals from damaging the differential pressure transmitters, a flexible diaphragm made of  materials that protects against pitting and stress corrosion cracking is used. Temperature may also need considered when working with differential pressure transmitters as outside temperature can cause the oil fill expands or contracts giving the sensor distorted and false pressure reading. Of course the sensing diaphragm on which the liquid pressure acts must be kept clean too.

For more about industrial process control sensors, see Instrumentation and Process Control Training article.

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Tuesday, March 8, 2016

Industrial Automation Control Software


Industrial Automation Control Software

should be...
Industrial Automation Control

Industrial automation control software's end-user design friendliness varies from vendor to vendor, and varies from PLC to PAC or other industrial PCs (IPC). But when it comes to answering the question, 'what should industrial automation control software be?', I agree with Jerry Reaves, of AutomationDirect...

Jerry: “They [End-Users] want to quickly install the software, connect to the controller and start programming, debugging or troubleshooting,” Reaves points out. “They don’t want to chase different software revisions, buy software upgrades or recite software revision levels to technical support.”
If you agree, let your voice be heard, share this with others.

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Sunday, February 7, 2016

PLC Program Backup

PLC Program Backup

After reviewing Industry 4.0: Risk I realize there is a lot to do for a manufacturing plant to prepare for Industry 4.0. Good advice is not to be overwhelmed and procrastinate, start somewhere. Start with the PLC Program Backup plan.

PLC Program copies
Only 1/3rd of manufacturing has all PLC Programs backed up!
Even if your manufacturing plant does not go for Industry 4.0 initiatives, insuring your have current backup copies of ALL of your facility's PLC and PAC programs will save you thousands in reduced future downtime. Idealistically you could also insure you have program backups for HMI and SCADA programs too.

The important thing is that you make a PLC program backup plan and start right away. Some improvement is better than none, so do your best and you will still profit from your work. To help out BIN95 offers a free PLC Maintenance Spreadsheet to inventory all your PLCs, checking attributes like last time PLC program was backed up, EEProm burned, battery changed, etc. etc. You can easily add your own attributes to the spreadsheet for example to additionally maintain PACs. (IE: Software require to access, firmware management, module revision numbers, IP address, network management, etc.)

Please, make a plan to back up your facility's PLC/PAC programs today.

Also be prepared, read Industry 4.0: Risk

Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .) Be sure to to stay on top!

Tuesday, November 24, 2015

PLC wiring tutorial: PLC safety circuit

PLC wiring Tutorial:

PLC safety Circuit

RE: CR1, E-Stop wired to PLC I/O

The software used in this video is from (PLC Training Certificate Course)

 Don (Follow me on Industrial Skills Training Blog and on Twitter @IndTraining .)Be sure to to stay on top!