Multi Point Interface

T

Thread Starter

tins

Folks, iam new to this field of control, and lookin more into MPI connection, this is wht kowledge i have
- MPI is connected b/w controllers (PLC's), , HMI, PC's
- Can have max of 32 nodes in the token ring n/w
- RS 485 is the protocol
- speed is 187.5 kbps
- MPI port on PLC

q1) wht is the port on the PC of connection?if PC does not have that port, do we use any converter
q2) wht is the lenght of the cable we can use, as to how far can we go
q3) and speed can be increased?
q4) wht is the internal wirin of the MPI comprised off?
q5) that is the only protocol we can use RS 485?


tahnks a lot,, made a big differnce in my life

thnks
 
q1) wht is the port on the PC of connection?if PC does not have that port, do we use any converter
Yes typicaly a Siemens CP card such as CP5611

q2) wht is the lenght of the cable we can use, as to how far can we go
Without repeaters 50m between terminating resistors on network.

q3) and speed can be increased?
This is dependant on PLC. If the port on PLC is MPI/DP then baud rate on MPI can be increased up to 12MB. In addition lengths in answer (2) also increase to those allowed by Profibus DP.

q4) wht is the internal wirin of the MPI comprised off?
Dont know, although I am sure it is in Siemens doc on internet.

q5) that is the only protocol we can use RS 485?
Not sure what you mean by this
 
G

Gerhard Bäurle

RS 485 is the physical specification for serial multipint connections. More information:
http://en.wikipedia.org/wiki/Rs485

MPI is a communication protocol definded by Siemens and based on the PROFIBUS protocol.

> q1) wht is the port on the PC of connection?

yes, there are serveral adapters availiable.

Our products for example:
http://www.deltalogic.biz/pbhw/netlink.htm
http://www.deltalogic.biz/s7-adapter/mpi.htm
http://www.deltalogic.biz/s7-adapter/usb-ada.htm

Siemens's product name is 'pc adapter':
http://support.automation.siemens.com/WW/view/en/10420976

> q2) wht is the lenght of the cable we can use, as to how far can we go

http://support.automation.siemens.com/WW/view/en/12907719

Best regards
Gerhard
http://www.deltalogic.bíz
 
L

Lothar (profichip)

Hi,

MPI is requested more & more, esp. by HMI Companies and Remote Programming Tools. thats why http://www.profichip.com started development in 2004 for a special ASIC called MPI12x which is now used by various applications. it's the only solution to support fullspeed @12Mbs!

rgds
Lothar
 
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