©contrinex 2013 - jdc ppt_lf_monitoringrwms different ways to monitor rwms j.-d. chatelain

©Contrinex 2013 - JDCPPT_LF_MonitoringRWMs

Different waysto monitor RWMs

J.-D. Chatelain

RMRp

VB

VB

200 mV

1V

4V

3.8V

1.2V

Possible values for VA

4V

Constraints:

1V < VA < 4V 1V < VB < 4VV = VA - VB > 200 mV

1.2V < VA < 4V 1V < VB < 3.8V

Biasing a Read/Write Module

VB

1 V

4 V

VB

200 mV

Twisted pair

Ro = infinite Ri = 120

Calculate: VA, VB and V

VB

V = 325 mVVA = 3.36 VVB = 3.03 V

VB = 3.03 V

Monitoring a Read/Write Moduleby means of a RS485 half-duplex output

DE and RE

DI

RO

VA - VB

Monitoring a Read/Write Moduleby means of a microcontroller

Multiplexing Read/Write Modules

Multiplexing Read/Write Modules… a more elegant solution

Each adaptor has its own virtual COM port

COM 1

COM 5

COM 1

COM 5

Connecting RWMs to a PLC with an ASCII driver

Aluminium shield

Read/Write Module

Motor

Connector

Shield

ShieldsRead/Write Module

Motor

Connector

Twisted pair

Twisted pair

Copper covering

Conform to the CEI/IEC 61000-4-4 level 3 standard

Strongly disturbed environment

Not recommanded

Recommanded

©Contrinex 2013 - JDCPPT_LF_MonitoringRWMs

Different waysto monitor RWMs

J.-D. Chatelain

End of this chapter