I-O Display Systems Basic I/O Product manual Squarewave, Pulse Generator, Extended capabilities

	Introduction 1
Squarewave	Can generate squarewaves with programmable On and Off
	periods. On and Off periods have a base range from 0.01 to
	2.56 seconds. Resolution can be further multiplied by a factor
	of 1-256 on a system wide basis. Re-triggering is available.
Pulse Generator	Can generate 1-65,535, 50% duty cycle pulses whose equal on
	and off periods can range from 0.01 to 2.55 Sec. Resolution can
	be further multiplied by a factor of 1-256 On a system wide
	basis.

Extended capabilities:

In addition to operating under the control of a host, Option/L of the BASIC I/O AD has the ability to perform local control functions without the host. Local control functions (LCFs) can insure the continued safe operation of closed loop control should the host of its communication link fail. In addition, LCFs can substantially reduce Host computational load or communications traffic.

Once characterized, Local Control Function blocks enable the BASIC I/O AD to perform control tasks without the constant involvement of the host computer. After configuration and activation via the host instructions, LCFs take data from their input ports, perform computations and send the results to their outputs where they may drive output modules, or other BASIC I/O AD internal functions.

Utilizing the LCF’s to perform simple logic tasks such as analog comparisons, summations, differences, sequence generating or state machine operations eliminates the need for programmable controllers or special purpose circuitry. This capability allows a more effective use of the host computer and its communication link because the LCFs handle the operation of the designated control function. In the meantime the host is only required to monitor over-all system status and generate the system displays and reports. This is particularly valuable for systems using modems for communications.

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