To start with KRC4 has build in EtherCat master insterface.
So your PLC needs to be working as Slave or you install EL6692 EtherCat bridge inside KRC4 to make it a slave to PLC.
Thanks for the response 
.In my project the PLC has to be the master. I shall order EL6692. Considering PLC to be the slave(just to try) how should i go about it. There are so many terminals as i see on KUKA controller. I could get a response back on X66. But read somewhere X65 must be used. And do i need to have work visual installed. Programming the robot is a separate task. All i need to do is send in a signal to the robot to execute the task/program number and reply back when its done..the kuka guy set up the robot in Automatic External Mode on the smartpad
You need EK1100 EtherCat coupler and EL6692 bridge.
You need WorkVisual installed.
It is used to configure your FieldBus (hardware) and INs and OUTs. No way around it.
Once you have hardware installed X65 is used for EtherCat communication between KRC4 and PLC (through gateway EL6692)
X66 is can be used for WorkVisual. It is Windows network interface (along with Profinet or Ethernet IP)
Let's back up a step: what communications options did this KRC4 come with? If none, then EtherCat is your only choice, and IIRC the robot can only act as an EtherCat Master, not as a Slave. The good news here is that at the communications protocol layer, Master/Slave just indicates who is controlling the communications, not the process -- the PLC could still be an EtherCat Slave to the robot, but still be bossing the robot around.
Most PLCs can be configured to act as either Masters or Slaves. Some can act as both at the same time, on different channels.
X65 is the EtherCat (KEB) connection. X66 is the KLI interface, which only works for a PLC connection if you have EtherNetIP or ProfiNet installed (it also serves for remote access, file transfers, etc). Which one are you trying to use?
You need EK1100 EtherCat coupler and EL6692 bridge.
You need WorkVisual installed.
It is used to configure your FieldBus (hardware) and INs and OUTs. No way around it.
Once you have hardware installed X65 is used for EtherCat communication between KRC4 and PLC (through gateway EL6692)X66 is can be used for WorkVisual. It is Windows network interface (along with Profinet or Ethernet IP)
EK1100 is not necessary. You can connect the EL6692 directly to the X44 interface.
@ Kr16_2: Thank you 
. Will go through it. I have a spare CX2020. Can i use it to try instead of EL6692?
@ SkyeFire : KRc4 did not come with any communiaction option.Yes. I know we can use PLC both as master and slave. I had used allenbradley as a slave with a small uv curing unit being the master.
I was trying with X66 but now will give it a try with X65.
So what i shall do is. I have ek1100 and cx2020. I shall connect these to X65 and give it a try.
Thanks a million guys. This project decides my career and i hope I can learn and do it.
KRC4 is unable to communicate directly with the CX embedded PCs, because there's no way to configure them to KUKAs EtherCAT bus. That's why you need the EL6692 between the CX and KUKA which can be configured at both sides.
EK1100 is not necessary. You can connect the EL6692 directly to the X44 interface.
Did not know that , thx
I am guessing I will need 24v provided to it.
As far as hardware config goes. KRC4 will plug to X1 while PLC will plug to X2 ?
Never tried it like that.
Can't remember if we had the KRC4 connected to the X1 or X2, but will check that tomorrow.
Spl : Thank you. Yes the one with cx didn't work either. And found out EK1100 is inbuilt in kuka controller. Now i have to get EL6692 and then connect to X65/X44 and try it. Didn't find X44 on controller though. Will check with the kuka people, if i can't connect it with x65. Will update once i cud do tat. Thanks
Your EK1100 is most likely plugged to X44.
Trace network cable from EK1100 and you will find X44 (network plug on KUKA CCU board - internal network switch)
Ok. So, we have the controller connected to the X1 port of the EL6692 but the X2 is empty because the bridge is installed to the CX PC, so it's using the CX's internal bus.
Connect the CX to the X67.1 and see if you can scan the bridge to the CX's project. If you can, then you configure the input/output messages that are sent through the bridge at CX's side and at KUKA's side. If I remember correctly, the message sizes should be multiples of byte. Also note that the input message at CX's side is the output message at KUKA's side, and same with the other way round.
Ok. So, we have the controller connected to the X1 port of the EL6692 but the X2 is empty because the bridge is installed to the CX PC, so it's using the CX's internal bus.
OK so most likely bridge alone will not function.
I need EK1100 and a bridge inside a KRC4.
thx
you don't need EK1100 in the krc4 if you don't want it....you can connect the KRC X44 bus directly to the(X1 port of) bridge installed on the external CX.
Hi All,
I could see some connection between kuka and beckhoff now. I could force in some values in beckhoff and see the values in workvisual. Now the next step. El6695 has FSOE variables. How shall i do the safety mapping etc.
I can have a safety project , ethercat safety plc el6900 and then.. wat next 
I think for this you need the special variant of the EL6695 that is sold by Kuka to support FSOE(maybe you have this?)
