Micro-PLC Analog Expansion Board Provides the OEM With A Low-Cost Way To Combine Digital and Analog I/O

Are you looking for a micro-PLC with digital input/output and analog capability? Many of Entertron Industries' customer were. So, the company developed the Smart-PAK PLUS analog expansion board. This board combines a micro-PLC with a wide range of analog I/O including thermocouple and RTD. Most micro-PLC's do not offer any capability, according to Stephen Luft of Entertron Industries. Those that have analog capability restrict the use of the high-speed counter when tapping the analog input. Furthermore, third-party analog modules used with micros require either the high-speed counter or an additional protocol to communicate between the two devices through digital I/O, a method Luft calls unreliable. "With the Smart-PAK PLUS there are no restrictions to any of the standard features or options and no additional protocols needed to incorporate analog I/O with digital I/O," Luft says.

Other advantages, claims the company, are size and price. Typically, in order to get more than one analog I/O, manufacturers would have to purchase a rack system when all that is required is a micro-PLC with additional analog capability. The Smart-PAK PLUS expansion board meets this need that was previously addresses only in larger expensive systems, claims the company. "We believe that the growing popularity of incorporating sophisticated analog applications with a minimum of digital I/O will continue as the capabilities of micro-PLC's expand," Luft says.

If additional I/O is required beyond the 8/6 offered, then the serial port on the Smart-PAK PLUS can be used to communicate to another Smart-PAK PLUS main board.

The Smart-PAK PLUS main board offers eight optically-isolated inputs (12-24 Vdc)/six relay outputs (5" x 7"). The outputs are individually commoned and rated at 5 A/output.

The new analog expansion board offers the following capabilities: Analog inputs (up to 8 channels): 0-5 V dc, 0-10 V dc, +/-5 Vdc, +/- 10 Vdc, or 4-20mA; analog outputs (up to four channels); 0-5 Vdc, 0-10 Vdc, or +/- Vdc. To of the four output channels can be configured for 4-20 mA. Up to four of the eight analog input channels can be configured to accept a thermocouple input. Type K is standard. Type J is available on request. Up to four of the eight analog input channels can be configured to accept RTD input. 100 ohm DIN (European) Curve is standard. American (US) Curve is available upon request.

Standard features include a full-function RS232 serial port that does not require an adapter, a 10 KHz high-speed counter, 4 K program capacity and a span rate of 15 msec/K of ladder instructions.

Options include Real-Tie Clock, expanded memory to 12K program capacity and second serial port (RS232 or two-wire RS485 for networking).

The main board for the Smart-PAK PLUS lists at $215 (one-piece OEM price). Several standard configurations, ranging from $ 75 to $ 695 additional, are available for the analog expansion board.

For more information, contact Stephen Luft, Entertron Industries, 3857 Orangeport Rd., Gasport, NY 14067, 716-772-7216.

January 1998 / Instrumentation & Automation News

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