Opto 22

43044 Business Park Drive, Temecula, CA 92590 USA
Local & outside the USA:(951) 695-3000
Toll-Free within the USA:(800) 321-6786
Fax: (951) 695-3095
Email: sales@opto22.com

New Communication Protocols Tech Note Answers Questions

Gongkong Interviews Opto 22

Schedule Your IO4AB WebEx Demo Today

Hot Tips from PSG: Initializing Values for Global Variables

New Communication Protocols Tech Note
Answers Questions

Communication protocols technical note

You know that Opto 22 products are built on open standards. And our controllers and brains support several communication protocols. But exactly which protocols can you use with a specific product?

Here's your answer. Our new technical note, Communication Protocols for Opto 22 Products, lists all the protocols we use and briefly describes each one. It also tells you which protocols each product supports.

The technical note includes both current products, like SNAP PAC controllers and E1 Optomux brain boards, and legacy products like FactoryFloor controllers and B1 brain boards.

Read the technical note.

Gongkong Interviews Opto 22

Gongkong industrial control website logo

On his recent trip to China, Opto 22's Bob Sheffres was interviewed by Gongkong, China's foremost industrial control website.

Gongkong is the most important source of industrial automation information in China, where automation is growing rapidly. Like automation.com here in the U.S., the site gives viewers news about all kinds of control products, companies, and trends.

Over the past couple of years Gongkong has sponsored PAC Summits in Nanjing, Shanghai, Beijing, and several other cities, where we've introduced our SNAP PAC controllers to Chinese engineers.

In the recent interview, Bob answers questions about how Opto achieves the high quality of its I/O, new opportunities in fields like infrastructure and energy, and Opto's representative office in Shanghai, opened in 2008.

Bob also mentions Opto 22's wired+wireless PACs, available this summer, and IO4AB (SNAP I/O used as remote I/O for Allen-Bradley PLC systems).

Read the interview (in Chinese).

Schedule Your IO4AB WebEx Demo Today


Have you seen how to use SNAP I/O as intelligent remote I/O with an Allen-Bradley PLC system? If not, here's a quick way to find out what it's all about.

There's no need to even leave the office. Just sit back and watch a live demonstration online. Our engineer walks you through setup and answers all your questions.

To schedule your WebEx online demo, just contact your local distributor or Arun Sinha at Opto 22 (phone 800-321-6786 or email asinha@opto22.com).

Hot Tips from PSG: Initializing Values for Global Variables

PAC Control

If you use PAC Control, you know all about variables. A variable holds a piece of data for your control program—the temperature reported by a thermocouple, parameters for communication, a string to be sent to a display, and so on.

Each variable stores the type of data you designate: floating point, integer, timer, string, pointer, or communication handle.

Variables may be global (the default) or persistent. In April we talked about why you might use persistent variables, and in May we gave you tips on initializing persistent variables. Now here's a tip on initializing values for global variables.

Initializing means setting the variable's starting value. When you first configured the variable, you chose its initial value. You also decided whether to initialize its value when you download a strategy, or every time the strategy starts running. But did you know which one to choose?

The key is understanding how the variable's value is stored.

Here's the Add Variable dialog box, where you make your choice:

Variable initialized on run

If you initialize the variable on strategy run, the initial value becomes part of the strategy. When the strategy is stored to flash memory on the controller, the variable's initial value is stored with it. The current value of the variable is not maintained in battery-backed RAM when the controller is turned off. When it's turned back on and the strategy starts running, the variable starts at its initial value.

Variable initialized on download

In contrast, if you initialize the variable on strategy download, the variable's current value is maintained in battery-backed RAM when the controller is turned off. When the controller is turned back on, the value starts off not at its initial value, but in its last state before power was shut off.

Questions? Comments? Contact Product Support.


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