How many variables can the PR200 handle as Modbus Slave?

It depends on the type of the variables. They can be either INT or REAL. An INT variable stores data in only one register, while a REAL variable requires two registers for this.

Since the PR200 as Modbus Slave have only 64 registers, it means the maximum number of variables is:

64 if you declare only INT variables

32 if you declare only REAL variables.

If there are both INT and REAL variables, you should calculate their maximum permissible number according to their combination. For example, if you declare 10 REAL variables, which is equal to 20 INT variables, you can declare up to 44 INT variables (64 - 20 = 44).