Fieldbus segment checkout form

Company/Location.................................................................................................................
Unit/Description......................................................................................................................
Controller number.................................................
Fieldbus card number...........................................Port number..............................................
Technician.............................................................Date.............Pass.......Fail.......
Step 1: Resistance measurement at the H1 segment conductors coming in from the field (1)
(+) to (-) signal Expected = > 50 KΩ (increasing) Actual =...............................
(+) to shield Expected = open circuit >20 MΩ Actual =...............................
(-) to shield Expected = open circuit > 20 MΩ Actual =...............................
(+) to ground bar Expected = open circuit > 20 MΩ Actual =...............................
(-) to ground bar Expected = open circuit > 20 MΩ Actual =...............................
Shield to ground bar Expected = open circuit > 20 MΩ Actual =...............................
Step 2: Capacitance measurement at the H1 segment conductors coming in from the field(1)
(+) to (-) signal Expected = 1 µF ( ± 20%) Actual =...............................
(+) to shield Expected = < 300 nF Actual =...............................
(-) to shield Expected = < 300 nF Actual =...............................
(+) to ground bar Expected = < 300 nF Actual =...............................
(-) to ground bar Expected = < 300 nF Actual =...............................
Shield to ground bar Expected = < 300 nF Actual =...............................
Step 3: Terminator switch verification

Terminator (Power Supply)

Terminator (Connection block)

Expected = Application dependent

Actual = On....Off.....N/A.......

Actual = On.....Off....N/A.......

Step 4: DC voltage measurement at power supply
(+) to (-) signal Expected:
  • 28-30 VDC for H1 with Integrated Power card or P+F Fieldbus Power Hub
  • 25-28 VDC for Relcom Fieldbus Power Supply
Actual =...............................
Step 5: AC measurement (waveform) power supply
(+) to (-) signal Expected = 500 - 900 mV pp Actual =...............................
(1) Some fieldbus segments with isolated couplers or barriers used in hazardous area applications, may indicate a low resistance measurement for "+ to - " and/or a high capacitance measurement for "+ to - ". These readings can be acceptable providing that the fieldbus signal's waveform and voltage compare to that shown in the sample waveforms.

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