Instructions:
The OP3 comes as standard with a 2.5 m long MPI cable. You can use this MPI cable for connecting an OP3 to an S7 and for the OP3's power supply. In this case, the OP3 does not need an external power supply.

There isn't a longer cable available in this form.

If you need a cable extension, you can use the following components.

• PROFIBUS cable
  (standard PROFIBUS cable - order number: 6XV1 830-0EH10, by the meter)
•  PROFIBUS connector
  (bus connector with axial cable end - order number: 6GK1 500-0EA02)
• Gender changer (9-pin female / female)
  The gender changer is needed if you want to connect the PROFIBUS cable to the OP3.

Note:
If you use a PROFIBUS cable as cable extension, the power to the OP3 must be supplied from an external connection.