After looking at another recent thread, it occurred to me that we all have different amounts of experience with different bus options on KRCs. So, I'd like to start a thread dedicated to the various advantages and disadvantages we've seen with different buses on different KRCs, with the intent of helping users with no previous experience select the right bus for themselves.
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KRC1/2:
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DeviceNet (MFC) :
Good: built into the MFC card (no extra hardware or software to buy), easy to set up and use (especially with the Telnet diagnostic commands).
Bad: Only works as a Master. Kind of obsolete and slow, these days. Really have to watch your cable lengths and termination resistance. Have to supply a high-quality 24VDC supply -- the 27VDC in the robot usually works for this, but not always. Slow to reconnect a disconnected module.
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DeviceNet (LPDN):
Good: easy to set up, Telnet commands available. Two channels per card (3 cards max), each channel can be configured as Master or Slave.
Bad: Same as DeviceNet MFC. Also, requires buying an add-in LPDN card for every 2 channels.
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Interbus:
Good: fast, robust (signal travels both directions around the ring architecture). Not very hard to set up by hand-editing the config files. Software utility from Phoenix Contact makes it even easier. Available in fiber-optic as well as wired.
Bad: Confusing addressing scheme. Devices are addressed by their physical location on the bus, so adding a new module in between old modules requires re-addressing everyone. Usually requires two cables (one out, one back) to complete the ring architecture. Requires buying a communication card.
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ProfiBus:
Good: Fast. Simple 2-wire cables. No bus power required. Slave config is easy.
Bad: Still have to be really careful about termination. Have to use confusing Siemens NCM software to configure Master network. Config file is not text, but proprietary binary format. Requires buying KUKA interface card and driver.
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RS232:
Good: Built in. Global standard. Very simple to use.
Bad: obsolete. Difficult to set up, especially since the rules changed with every controller version. String formatting/decoding can be tricky.
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EIP: (don't know much about this one)
Good: Uses ethernet cable and IP addressing, standard. Fast and robust.
Bad: very difficult to set up, few people with experience in doing it on a KRC2. Not sure if it's available for KRC1 at all. Requires add-on card
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EKX (Ethernet-KRL-XML):
Good: Ethernet cable, IP addressing. Robust. Can be used with built-in Ethernet port, or with add-on Realtime Ethernet port. Uses standard network-style port-based communications, so easiest way to connect to a computer application, as opposed to a PLC. Sends/receives large blocks of data in user-defined XML format.
Bad: Tricky to get working. Not as robust as Fieldbus, especially for steady-flow background communications. Not a whole lot of user field experience to draw on. Not available for KRC1 (I think).
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RSI:
Good: Just about the only way to perform realtime communications with a computer. Works just like EKX, but as a hard-realtime cyclic communication scheme.
Bad: Same as EKX, but trickier due to the tight timing constraints, and doesn't have the steady-flow issues.
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KRC4:
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DeviceNet:
Good: Still easy to setup and use
Bad: Same as KRC1/2, but worse: have to buy an add-on bridge module, and no more Telnet bus-scan commands
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ProfiBus:
Good: Same as for KRC2. Also, easier to configure with WorkVisual than with the old NCM software
Bad: Kind of slow and obsolete compared to ProfiNet and EIP. Requires add-on hardware
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ProfiNet:
Good: No extra hardware required. Ethernet cabling and IP addressing. Easy to config with WorkVisual
Bad: Requires buying additional KUKA software. Cannot coexist with EIP on the same robot. No multi-master support
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EIP:
Good: Same as Profinet, but has multi-Master support.
Bad: Requires buying additional KUKA Software, cannot coexist with ProfiNet on the same robot. Rather slow on re-connecting disconnected devices
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RS232:
No longer exists on the controller. Could probably buy an EtherCat-to-RS232 bridge, but I've never seen this done (yet).
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EtherCat:
Good: built in to robot, no extra hardware or software required. Ethernet cabling and IP addressing.
Bad: Haven't used it myself, but am told that it does not support disconnecting/reconnecting slave devices.
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EKX:
Good: Much improved over KRC2. Better command architecture, better error trapping and handling. Can now send non-XML "telnet-style" strings. Can act as Server or Client. Multiple "environments" for operating.
Bad: Still tricky to do the first time, especially if you don't have any experience with XML or PC-based network applications.
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RSI:
Just like EKX, but hard-realtime. Easy on the robot end, but requires tight server-side programming on the PC end.