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