Download Fluke 19xC-2x5C

Appendices
Bushealth Measurements
A
Modbus IEA-232/RS-232.
Modbus IEA-485/RS-485.
Is in use in Process Industry, Building and Factory
Automation. Modbus RS-232 is used for point-to-point
communication. System layout is shown in the figure
below. Continuous data traffic is not ensured.
Is in use in Process Industry, Building and Factory
Automation. Modbus System layout is shown in the figure
below. Continuous data traffic is not ensured.
DATA +
TxD
CONTROLLER
RxD
GND
DEVICE UNDER
CONTROLLER
DATA -
DEVICE 1
DEVICE 2
GND
CONTROL
Modbus IEA-232/-RS-232
To check this type of bus, ScopeMeter Channel A is on
and DC coupled. The recommended probe is the Fluke
10:1 probe. Connect the probe as shown below.
Modbus IEA-485/-RS-485
To check this type of bus, ScopeMeter Channel A and B
are on and DC coupled. The recommended probes are
Fluke 10:1 probes.
TxD or RxD
GND
Connect the probes as shown below.
DATA +
DATA DATA GND
In case there are handshake lines, they can be measured
as well as far as V-Levels are concerned.
A-5