AB7660 Modbus Plus Global Data In Exceeds 64 Bytes

I have a project that requires me to replace an existing Modicon 984 PLC that has a significant amount of crosstalk between other PLCs on the Modbus-plus network.

The PLC is configured with 153 16-bit words as global data in, as well as 29 16-bit words as global data out:

I’m doing a feasibility check, and currently I can’t add any more than 64 bytes in the global input data area in the anybus x gateway configurator.

On the product sheet, the AB7660 touts that it is capable of 512 bytes of bi-directional I/O - Is there another product that perhaps has the ability to receive more than 32 16-bit words of global data?

Thank you.

The device is only capable of 32 words (64 bytes) of Global Data:

From page 8 in the User Manual:

Unfortunately, this is the only Modbus Plus slave interface that we have. Is it possible to exchange some of this data as parameter data instead?

I’m not certain I can move the data from all of the PLCs on the line to communicate via parameter data - pretty unlikely though. Reading through the documentation, I also noted that you use dip switches for the source, does that mean it can only receive global data from a single source? And instances where two or more devices are putting global data in the token ring, it can only pick up one contiguous list of bytes from the predefined source address?

For Incoming Global Data, yes:

Outgoing Global Data can be read by any node: