SYSTEM E_RDELAY_STATS

E_RDELAY_STATS

This System Configuration gathers and displays statistical data on the timing performance of an instance of the E_RDELAY 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 RELOAD_DLY + DT1 in Test Cases 1, 2, and 3, and DT0 in Test Case 4. 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 RELOAD_DLY + DT1 + 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.
  • RELOAD_DLY: The interval between the first and second occurrences of a START event issued to the E_RDELAY instance in each test.
  • N: The number of tests to be performed.
  • DT0: The DT value upon the first occurrence of a START event issued to the E_RDELAY instance in each test.
  • DT1: The DT value upon the second occurrence of a START event issued to the E_RDELAY 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 RELOAD_DLY DT0 DT1
1 20 t#1s t#200ms t#750ms t#300ms
2 40 t#250ms t#100ms t#225ms t#25ms
3 100 t#100ms t#20ms t#75ms t#30ms
4 100 t#100ms t#20ms t#75ms t#0ms
Table 4 - Test Results (milliseconds)
Test No. Platform MEAN SD MIN MAX
1 RPI3B 500.68 0.16 500.62 500.76
BOD 500.73 0.23 500.67 500.86
W10 515.62 0.28 514.45 515.81
W10B 500.49 0.45 500.02 501.69
2 RPI3B 125.61 0.06 125.55 125.77
BOD 125.68 0.08 125.62 126.00
W10 140.62 0.22 140.12 141.02
W10B 125.28 0.48 125.02 126.90
3 RPI3B 50.60 0.09 50.49 50.96
BOD 50.70 0.15 50.51 51.98
W10 62.47 0.29 61.27 63.00
W10B 50.45 0.55 50.00 51.97
4 RPI3B 75.32 0.08 75.27 75.58
BOD 75.36 0.14 75.21 76.75
W10 78.13 0.32 76.87 79.01
W10B 75.12 0.20 74.96 75.98

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,TIME,UINT,TIME,TIME PERIOD, RELOAD_DLY,SAMPLES, DT0, DT1
E_RDELAY_STATS.TEST_PARAMS
E_RDELAY_STATS.TESTER
E_RDELAY_STATS.STATS