Fluke 125 - Modbus IEA-232;RS-232

Fluke 125
Users Manual
A-6
below shows a typical system layout. Data traffic is
continuous.
To check ControlNet, ScopeMeter Channel A is on and
DC coupled. The recommended Banana to BNC Adapter
BB120 (1:1) allows Channel A to connect with BNC
cables. To connect to the System Under Test use a
PM9083 male BNC to dual Female BNC adapter (T-
piece, optional), and an extra BNC cable (PM9092,
optional) as shown in the figure below.
Bear in mind that in ControlNet cabling must not be
disconnected during normal process operation. Some
systems provide a Coaxial Breakout to make connection
to BB120. Use a short coaxial cable to minimize load on
to the system.
COAX
COAX COAX
PM9083
BB120
PASSIVE
TAP
PASSIVE
TAP
DEVICE 1 DEVICE 2
Modbus IEA-232/RS-232.
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. To check
this type of bus, ScopeMeter Channel A is on and DC
coupled. The recommended probe is STL120 (1:1). The
probe tip must be connected to the Tx (Transmit) or Rx
(Receive) wire; the COM input (or Black Ground Lead) to
the Signal Ground. In case there are handshake lines,