Hi,
sorry to jump in a little late on the conversation. I have seen people trying to use the Modbus serial communication but found out that Ethercat was easier to use and saved them a lot of programming time. Here is some information how the 2F Robotiq gripper is installed on IIWA using Ethercat:
This how-to is intended for the Robotiq 2-Finger 85/140 3.X.X, the Robotiq Universal Controller 4.X, Kuka IIWA media flange and Kuka Sunrise Cabinet
What you need :
Robotiq 2 finger 85 gripper
Coupling for the gripper AGC-CPL-062-002
Communication cable CBL-COM-2067-10 (for connection with the controller)
Robotiq Universal Controller UNI-CTR-001-ECAT
How to do it :
Mechanical Assembly
Install the coupling of the gripper on the Kuka IIWA wrist.
Install the gripper on the coupling.
Electrical and Communication installation
Kuka’s communication protocol is EtherCAT. So you need to convert the RS485 signal to EtherCAT.
Plug the Robotiq gripper's pigtail to the Robotiq communication cable.
Plug the combicon on the other end of the communication cable in the Robotiq controller.
Use the X65 EtherCAT port on the Kuka Sunrise cabinet to connect to the Robotiq controller
Configure the inputs/outputs in WorkVisual
And you are good to go in Sunrise OS V1.5.
To use the Kuka IIWA electrical media flange in-arm wiring attached is the electrical schematic.
We actually use ports X34 and X35 on the media flange for the power and 485 +/- signals, since this allows us to use the X76 connection at the base of the IIWA arm, which is for external power/data connections.
X651 is directly connected to the robot controller's X650 port and allows for powering and communicating with EtherCAT devices at the media flange.
Since the gripper itself communicates with RS485, we only need to use the shielded pair for the serial comm.
Hope this helps.