BECKHOFF PT100 - Manual (Page 8)

PT100 4-fold temperature measurement Beckhoff II/O System
Page 8 of 10 Version : 1.1 Date : 12 March 97
4. Installation instructions
Assembly
The PT100 module is connected to the II/O fibre-optical guide ring by means of fibre-optics
cable plug-in connectors (Toshiba). The maximum fibre-optical cable length to the adjacent
boxes should not exceed 45 m if plastic fibre-optical light guides are used and 600 m in the
case of glass-fibre. These values are only valid if bending radii of at least 30 mm are complied
with when running the fibre-optical cable. No special tools are required for attaching the
connectors if plastic fibre-optical light guides are used.
The Pt100 sensors are directly connected to the inputs (connector X 20) using two- or four-
conductor cable (cf. wiring diagram).
Assembly of the PT100 module is performed by means of distributed configuration on the
unit or in the switchgear cabinet by simply snapping it onto a device mounting rail as
specified in DIN EN 50022 or DIN EN 50035.
Configuration
The D0 and D1 data bytes are entered into the configuration list as inputs and the D2 and D3
are entered as outputs.
The D0 and D1 data bytes of the II/O message contain the data of the four measurement
values (multiplexed).
Data byte D2 is used for selection and acceptance of the data of a measurement channel. In
addition, the D2.7 key may be used to reset the microprocessor.
Data byte D3 is presently unassigned (spare slot).
Supply voltage
A tripolar connection terminal with ports for the control logic / analog portion is provided for
connecting 24V supply voltage (+) and ground (-) (connector X10). Connector X10 pin 3 is
unassigned.