D5093
- SIL 3 Loop Powered 24 to 220 Vac /Vdc Switch Repeater Transistor Out
G.M. International ISM0175-7
6
The proof test shall be performed to reveal dangerous faults which are undetected by diagnostic. This means that it is necessary to specify how dangerous undetected faults, which
have been noted during the FMEDA, can be revealed during proof test. The Proof test consists of the following steps:
Testing procedure at T-proof
Steps
Action
1
Bypass the safety-related PLC or take any other appropriate action in order to avoid a false trip.
2
Connect a variable DC / AC source to any input terminals couple (7-8 for D5093S and 7-8, 9-10 for D5093D). Connect the positive output terminals (1 for
D5093S and 1, 3 for D5093D) to the series of a current limiting resistor (i.e. 1 k
Ω
) and the positive pole of a DC voltage generator (i.e. 24 Vdc); then connect
the output negative terminals (2 for D5093S and 2, 4 for D5093D) to the negative pole of the DC voltage generator. Measure, by means of a DC voltmeter, the
voltage difference between any output terminals couple (1-2 for D5093S and 1-2, 3-4 for D5093D).
During normal operation, when the input DC / AC voltage amplitude is comprised between 18 Vdc / Vrms and 250 Vdc / Vrms (maximum allowed value for the
module safe operation) and the appropriate threshold is selected, by means of the internal dip-switch, in accordance with the applied input signal, the output
open-drain transistor is in the closed state. In this condition, a voltage drop lower than 1.0 Vdc should be measured between the output terminals and the yellow
status LED is lit.
Then, when the input DC / AC voltage amplitude falls below the related lower threshold value, the output transistor turns to the open state. In this condition, a 24
Vdc voltage drop should be measured between the output terminals and the yellow status LED is turned off. Once the lower threshold voltage is reached, the
following two possible fault situations can happen:
1) if the status LED has been turned off, but a low value voltage is still measured between the output terminals, then a dangerous failure which has shorted
the output terminals is detected;
2) if the status LED is lit again and a low value voltage is still measured between the output terminals, then a dangerous failure which has excessively lowered
the comparator stage threshold is detected.
Repeat this test for all of the five possible threshold voltage levels (each one of them corresponds to a different position of the dip-switch selector).
3
Use the same setup described in the previous step and measure, by means of an AC voltmeter, the rms value of the output voltage. In normal operation, both
when the output open-drain transistor is in the open or closed state, the output voltage measured at terminals 1-2 of D5093S or 1-2, 3-4 of D5093D should have
no AC components, that is its rms value should be ideally null. If an rms value well above 0 Vrms is measured (a reasonable value could be 50% of the voltage
which supplies the output circuit, i.e. 12 Vrms compared to 24 Vdc), a dangerous failure which has produced an oscillation of the internal comparator stage
output is detected.
4
Restore the loop to full operation.
5
Remove the bypass from the safety-related PLC or restore normal operation.
This test reveals almost 95 % of all possible Dangerous Undetected failures in the module.
Configuration
D5093S/D
ON
ON
CH. 1
CH. 2
(for D5093D)
Threshold level 1
(24 Vac/Vdc typical)
1 = ON, 2 = 3 = 4 = 5 = OFF
1 2 3 4
ON
OFF
DIP switch configurations (all valid for SIL applications):
5
Threshold level 2
(48 Vac/Vdc typical)
2 = ON, 1 = 3 = 4 = 5 = OFF
1 2 3 4
ON
OFF
5
Threshold level 3
(60 Vac/Vdc typical)
3 = ON, 1 = 2 = 4 = 5 = OFF
1 2 3 4
ON
OFF
5
This mode is
factory settings
Threshold level 4
(110 Vac/Vdc typical)
4 = ON, 1 = 2 = 3 = 5 = OFF
1 2 3 4
ON
OFF
5
Threshold level 1
(220 Vac/Vdc typical)
5 = ON, 1 = 2 = 3 = 4 = OFF
1 2 3 4
ON
OFF
5
DIP switch positions 6 to 8 are not used.
