Hi,
My first post here, although I have been using these pages a lot over the last few weeks as I'm trying to get more familiar with PLC work. There has been a lot of useful info, but I couldn't find the answer to this question.
I am a complete novice and don't really know what I'm talking about, so please go easy!
I am trying to use a Micrologix (A) PLC to control a Parker SSD 890 Drive. The drive only has a Modbus communications card, and the ML only does Ethernet/IP. I know the sensible option is to buy an Ethernet/IP card for the drive and then use Messages to communicate, but I do need to get this working quickly, and can't wait for spare parts. We also have a Red Lion G3 HMI unit which seems able to communicate with both the PLC and Drive, in their respective languages. I thought, naively, that I could send certain integers to tags in the HMI, use the internal programming there to map them over to the tags which are sent to the drive. But now I see that the tags being sent to the drive are holding registers, not integers, so the HMI programming can't do this mapping.
Does anyone know which data format in the PLC is compatible with holding registers which are being sent over Modbus? Are Long Integers compatible with holding registers?
I'd be very grateful for any pointers, especially those which aren't 'go and buy the right equipment'!
Thanks!
Mowgli
My first post here, although I have been using these pages a lot over the last few weeks as I'm trying to get more familiar with PLC work. There has been a lot of useful info, but I couldn't find the answer to this question.
I am a complete novice and don't really know what I'm talking about, so please go easy!
I am trying to use a Micrologix (A) PLC to control a Parker SSD 890 Drive. The drive only has a Modbus communications card, and the ML only does Ethernet/IP. I know the sensible option is to buy an Ethernet/IP card for the drive and then use Messages to communicate, but I do need to get this working quickly, and can't wait for spare parts. We also have a Red Lion G3 HMI unit which seems able to communicate with both the PLC and Drive, in their respective languages. I thought, naively, that I could send certain integers to tags in the HMI, use the internal programming there to map them over to the tags which are sent to the drive. But now I see that the tags being sent to the drive are holding registers, not integers, so the HMI programming can't do this mapping.
Does anyone know which data format in the PLC is compatible with holding registers which are being sent over Modbus? Are Long Integers compatible with holding registers?
I'd be very grateful for any pointers, especially those which aren't 'go and buy the right equipment'!
Thanks!
Mowgli