HEllo all !
I have got a TP170B (colour) connected to a S7-224 plc (only got 1 port) - so I am using a profibus cable (only 2 cores red & green) with "piggy back" connectors each end that have the terminating resistors in.
I have got comms on both the TP170 and the PLC set to PPI, 187.5kbps, highest station = 31,
PG/PC (Laptop) = node 0,
PLC = node 1
TP170 = node 2
I am using CP5511 pcmcia adaptor card in my laptop to connect to plc (PG/PC interface set to PPI comms as above)
I have the profibus/ mpi (its purple !) connected from TP170 to plc, and my laptop plugs into the top of the piggy back connector on plc.
Now whilst the laptop is plugged in and communicating with the plc, the TP170 screen is FINE ! But as soon as I power down Microwin or drop the connection to the PLC,or switch off laptop, the TP170 loses its connection and shows "no peer at address" !
Why is that !?
I have tried having the terminating resistors in various positions ON / OFF etc at either end of cable - but to no avail.
Also can someone please explain what the rule is exactly about when Terminating resistors should be on or off !? I find sometimes things work either way, and sometimes they DONT work in either position !
IF the terminating resistor is on the plug connected to the plc should it be ON or OFF ? SAme question applies to the HMI screen !?
Hope someone can shed some light on it for me,
Thanks,
STeve
I have got a TP170B (colour) connected to a S7-224 plc (only got 1 port) - so I am using a profibus cable (only 2 cores red & green) with "piggy back" connectors each end that have the terminating resistors in.
I have got comms on both the TP170 and the PLC set to PPI, 187.5kbps, highest station = 31,
PG/PC (Laptop) = node 0,
PLC = node 1
TP170 = node 2
I am using CP5511 pcmcia adaptor card in my laptop to connect to plc (PG/PC interface set to PPI comms as above)
I have the profibus/ mpi (its purple !) connected from TP170 to plc, and my laptop plugs into the top of the piggy back connector on plc.
Now whilst the laptop is plugged in and communicating with the plc, the TP170 screen is FINE ! But as soon as I power down Microwin or drop the connection to the PLC,or switch off laptop, the TP170 loses its connection and shows "no peer at address" !
Why is that !?
I have tried having the terminating resistors in various positions ON / OFF etc at either end of cable - but to no avail.
Also can someone please explain what the rule is exactly about when Terminating resistors should be on or off !? I find sometimes things work either way, and sometimes they DONT work in either position !
IF the terminating resistor is on the plug connected to the plc should it be ON or OFF ? SAme question applies to the HMI screen !?
Hope someone can shed some light on it for me,
Thanks,
STeve