[?]: connection between PC <---> cpu 224

[PLC_ITA]

Hello friends, i need a suggest to connect my pc with cpu 224

I do not have a big experince with 200 series, only 2-3 time used an old cpu 215 2dp.

I use a rs232 <--> PPI converter and microwin.

When I try to connect with the CPU 224, this is not found. The software will scan the entire address, but can not find the CPU.
I tried to change the baud rate but to no avail.
if I try to connect the same PC and ppi converter with a other cpu215 all is ok
The software on the CPU 224 has not been done by me, I would just save it for a backup, and i need to modify a timer
anyone has any suggestions for me ?

thankyou in advance

[bilbo_321]

The comm port(s) of S7-22x CPUs can operate in 2 modes: PPI and freeport.
If the port is set-up for freeport communication you can't connect using PPI protocol and MicroWin.
But the good thing is if PLC is in STOP, it automatically switches port to PPI mode, so try to connect when PLC is stopped.

[PLC_ITA]

hi, opps, this is a problem. the plc is in run! and during the day it' not possible to put in stop.
it's a easy application 2-3 motor a 3/4 photocell.
is there a possibility to connect if the port is setting "freeport" ?

if i put in stop the plc, are there problems to re put in run aftter connection in ppi ?

thank you for your help

PLC_ITA

[peterc101]

hi ,

after connecting in PPI , starting up the cpu should not be a problem , the configuration of the port is in the program and happens in the first cycle , just like OB100 in S7 300
i would find it strange though if youre cpu is programmed for freeport if its not communicating with anything during normal operation

[bilbo_321]

Hi PLC_ITA,
Just find a proper time to switch PLC to STOP (during plant maintenance for example).

What peterc101 wrote is correct.

Are there any devices connected to the PLC port?
It could be used for USS communication to VSD (variable speed drive).

[hmohamed]

hi PLC_ITA

the cpu may uses a higher baud rate than in your ppi cable
try to change the PPI cable

[PLC_ITA]

thank you to all.

saturday, i hope to ha a possibilities to switch off the plant.
there is'nt connection into ppi port.
I have already tryed to change a baudrate without result. i'have change the baudrate from microwin. it's correct ?
there are other way to change a baudrate ?

thank you again for your help

[bilbo_321]

I suppose that PLC port is set to baudrate of 187,5 kb/s, as there are no devices connected to it. CPU 224 supports baudrate up to 187,5 kb/s.
The bad news is that you can't connect using old RS-232/PPI cable. You should use RS-232/PPI Multi-Master or USB/PPI Multi-Master cable or PC Adapter USB or communication processor like CP 5512 or CP 5611.

[hmohamed]

i think bilbo_321 is right i had already faced this problem before and solved when i used PPI/USB cable

[PLC_ITA]

thank you to all,
i have install microwin in other laptop usually used for s7 300/400 where i have a 5512 card.

to connect microwin with 224, i need a special cable or i can use the same cable used for s7-300/400 ?

PLC_ITA

[bilbo_321]

use the same MPI cable.

[PLC_ITA]

HI bilbo, thank you for your help, all ok . 187 k communication speed, with 5512 all ok