SYSTEM E_DELAY

This System Configuration gathers and displays statistical data on the timing performance of an instance of the E_DELAY Function Block (FB) type (DLY_FB in the TESTER Resource). Table 4 presents the statistics obtained by running the test parameter sets listed in Table 3 on the platforms listed in Table 2 with the specified Java Virtual Machine (JVM) versions.

In the ideal situation for event handling function blocks described in Annex A of IEC 61499-1, the value of the CHRONO.ET output upon the occurrence of an event at the CHRONO.EO output in the TESTER Resource would be DT. However, it is apparent from Table 4 that overheads and indeterminacies of event processing and delay scheduling are causing the actual CHRONO.ET value to be DT + x, where x is a randomly distributed variable with a mean value less than 1 millisecond on all tested platforms except W10.

Table 1 - Test Parameters
`PERIOD:` The interval at which tests are to be performed. `N:` The number of tests to be performed. `DT`: The `DT` value upon the occurrence of a `START` event issued to the `E_DELAY` instance in each test.

Table 2 - Test Platforms
Platform	OS	CPU	Bits	GHz	Cores	JVM
RPi3	Raspbian	BCM2835 (ARM7)	64	1.4	4	1.8.0_212
BOD	Bodhi Linux™	Intel® Celeron®	32	2.53	1	1.8.0_91
W10	Windows 10	Intel® Celeron® N2815	64	1.86	2	1.8.0_222
W10B	Windows 10	Intel® Core™ i-2630QM	64	2.00	4	1.8.0_222

Table 3 - Test Parameter Sets
Test No.	`N`	`PERIOD`	`DT`
1	20	`t#750ms`	`t#500ms`
2	50	`t#200ms`	`t#100ms`
3	100	`t#100ms`	`t#50ms`
4	200	`t#50ms`	`t#25ms`

Table 4 - Test Results (milliseconds)
Test No.	Platform	`MEAN`	`SD`	`MIN`	`MAX`
1	RPI3B	`500.27`	`0.0`	`500.23`	`500.52`
	BOD	`500.17`	`0.0`	`500.16`	`500.22`
	W10	`500.49`	`0.43`	`499.88`	`501.18`
	W10B	`500.49`	`0.45`	`500.02`	`501.69`
2	RPI3B	`100.24`	`0.03`	`100.21`	`100.28`
	BOD	`100.17`	`0.06`	`100.15`	`100.26`
	W10	`100.47`	`0.34`	`100.02`	`101.51`
	W10B	`100.90`	`0.11`	`100.29`	`100.97`
3	RPI3B	`50.22`	`0.03`	`50.20`	`50.38`
	BOD	`50.18`	`0.12`	`50.14`	`51.33`
	W10	`50.46`	`0.34`	`49.94`	`51.45`
	W10B	`50.16`	`0.27`	`49.96`	`50.98`
4	RPI3B	`25.25`	`0.05`	`25.20`	`25.68`
	BOD	`25.20`	`0.10`	`25.15`	`26.21`
	W10	`25.53`	`0.50`	`24.41`	`28.88`
	W10B	`25.25`	`0.33`	`24.97`	`26.06`

This System configuration uses the Local Multicast design pattern for the communication of data and events among Resources. The FBDK uses the Tagged Data design pattern to ensure consistency of the communicated events and data, as shown in the table below.

Tag Name	Type(s)	Description
`ET`	`TIME`	`Elapsed Time from Chronometer`
`START_TEST`	`TIME,UINT,TIME`	`PERIOD, SAMPLES, DT`