Tia portal v.13 sp1

cpu 1211c

cm 1241 rs485

daikin ed15121-9

Hi

I am trying to set up a Modbus rtu network with a 1200 plc as master and 3 daikin water chillers as slaves what I am unsure about is terminating resistors. Do I need a resistor for the cm1241? how do I know what size? and if it needs one, do I solder it between pins 3 and 8 of the 9 pin d-sub? Also (although I know this is not siemens) on the Daikin controllers when I set up the Modbus parameters (parity, baud rate etc.) there is a parameter to set terminating resistor on/off, is this setting an internal resistor or is just letting the comms module know that it is the last slave on the network and I have to connect an actual resistor to the terminals?

thanks