Fluke 190 [84/159] Rs 485 bus mod bus iea 485 rs 485

Fluke 19xC-2x5C

Users Manual

RS-485 Bus & MOD Bus IEA-485/RS-485

Default probe setting 10:1. Use the Fluke 10:1 probes.

1 Connect the red probe to the test tool input A

and the grey probe to input B.

2 Connect the ground lead of the input A probe to

the RS-485 bus RxD/TxD N (-)

3 Connect the ground lead of the input B probe to

the RS-485 bus cable shield.

4 Connect the probe tip of both probes to the

RS-485 bus RxD/TxD P (+)

DATA

DATA -

DATA GND

Figure 40. RS-485 Bus Measurement Connections

Table 6. RS-485 Bus Tested Signal Properties

Signal Description

V-Offset High level voltage

V-Level Peak-peak voltage

Data Bit width

Rise Rise time as % of bit width

Fall Fall time as % of bit width

Jitter Jitter distortion

Signal Dist.

Overshoot

Signal distortion (Manchester

decoding, default setting)

Overshoot (NRZ decoding, can be

selected via limit setup)

Note

Continuous data traffic is not ensured . See

Data

Traffic on page 70