difference between mitsubishi FX1 & FX1s

Dear all,
hi to all PLC experts! I am trying to connect to proface HMI with my mitsubishi FX1s PLC but always failed to connect.
the HMI manual does not include the FX1s model in the allowable PLC to be connected. only the FX1 model.
i just want to know if these two models are in different or the same family model?
regards,
Ivel

There is no difference in protocol. I would presume that it means the FX1 family, as there is also a FX1N

btw, i can communicate to this PLC using OPC server using the cable provided by vendor. this cable has some circuit boards inside. on the other hand, the cable for PLC-HMI connection is just my design (based on serial 422 standards).

I think I need the vendor-type cable for PLC-HMI.
My problem is, the vendor-type cable has an output of the following:
1.) PLC - Rx, Tx, Gnd, DTR, DSR
2.) HMI has no DTR & DSR in its cable config. (Gnd, Tx, Rx, RTS, CTS, CD, ER)

can i connect DTR/DSR to CTS/RTS?