G’Day all,
Just would like to get your opinions / experiences on the following, A customer has asked for us to check out the possibility of using one PLC for 2 x machines, typically we use a dedicated PLC for each machine.
Some background:
We are an OEM for the plastics industry mainly Automotive, we have previously and currently built some machinery for an automotive interior application with 4 x variants : Right hand Front machine, Right hand Rear machine, Left hand Front and Left hand Rear, simple so far.. we utilised separate S7-300’s & TP170’s in each machine typical IO count of 192 each machine, the physical layout has been 4 x separate machines. OK The customer has asked to check out the possibility of using one PLC for 2 x machine eg Right Hand Front & Right Hand Rear. My initial concerns are of flexibility, also uptime, if one machine were to go down (Not that they would but if !!!) then the machine in question may have to be powered down to facilitate repairs thus causing downtime on the second machine, god forbid there was a requirement for software mods. I have no real problem with the PLC controlling two operations however my programs have been time sensitive in the past.
Now I would believe the IO count would simply be doubled 192+192= 384 , ok but the savings on a CPU compared to the issues above I don’t believe in our application are worth it, I still believe that 2 x HMI’s would be required as there are a lot of separate parameters and alarms required for each machine, but hey I’m only the designer……
Any thoughts ?????
Cheers
Just would like to get your opinions / experiences on the following, A customer has asked for us to check out the possibility of using one PLC for 2 x machines, typically we use a dedicated PLC for each machine.
Some background:
We are an OEM for the plastics industry mainly Automotive, we have previously and currently built some machinery for an automotive interior application with 4 x variants : Right hand Front machine, Right hand Rear machine, Left hand Front and Left hand Rear, simple so far.. we utilised separate S7-300’s & TP170’s in each machine typical IO count of 192 each machine, the physical layout has been 4 x separate machines. OK The customer has asked to check out the possibility of using one PLC for 2 x machine eg Right Hand Front & Right Hand Rear. My initial concerns are of flexibility, also uptime, if one machine were to go down (Not that they would but if !!!) then the machine in question may have to be powered down to facilitate repairs thus causing downtime on the second machine, god forbid there was a requirement for software mods. I have no real problem with the PLC controlling two operations however my programs have been time sensitive in the past.
Now I would believe the IO count would simply be doubled 192+192= 384 , ok but the savings on a CPU compared to the issues above I don’t believe in our application are worth it, I still believe that 2 x HMI’s would be required as there are a lot of separate parameters and alarms required for each machine, but hey I’m only the designer……
Any thoughts ?????
Cheers