Honeywell VRX180 user manual #16

Programming and Operating Concepts

Also typical in the execution of a set point profile is the generation of discrete events during each profile step. Discrete events are simply status indicators that are programmed to assume either an ON or OFF state during a step of a profile. As simple discrete status indicators, these events may, for example, be used to initiate a logic control scheme on the process being controlled upon the occurrence of a particular profile segment. In this product, note that up to 16 discrete events may be programmed per segment. See Figure 3-26.

&	∋	(	)	∗
PROCESS
VALUE IN
ENGINEERING
UNITS
		TIME
SEGMENT	SEGMENT	SEGMENT	SEGMENT	SEGMENT
#1	#2	#3	#4	#5

SP1 EVENT	ON	OFF	ON	ON	OFF
#1

•	•	•	•	•	•
•	•	•	•	•	•
•	•	•	•	•	•
SP1 EVENT	OFF	ON	ON	OFF	ON
#16

Figure 3-26 Up To 16 Discrete Events May Be Programmed Per Step Of A Set Point Profile

Discrete events, whose ON or OFF states depend on the step number of the profile they are associated with, may be externalized using the discrete output hardware available in the instrument. Figure 3- 27features the function block diagram elements that represent how to program the instrument’s discrete outputs so that their states coincide with those assumed by a profile’s discrete events.

72 Video Recorder – User Manual