1770-KFD and 1747-SDN - cannot set driver

**Bolty**

Member
Join Date
Feb 2005
Location
Scotland
Posts
46
Evening all,

I'm hoping someone can point me in the right direction with this issue where I cannot set up a 1770-KFD driver in RSLinx without getting a KFD32 error.

I thought it was time to get my head around some Devicenet principles and at least how to connect to the 1747-SDN scanner card and at least be able to upload / download configs so dragged out a brand new SDN card and a brand new SLC processor from my stock squirreled away.

I've set up on my test rig a SLC 5/05 processor and the 1747-SDN scanner card with nothing else fitted. I have also made up a 3 metre length of correct spec devicenet cable running from the scanner card to my 1770-KFD rs232/devicenet convertor. The devicenet connector also has the 24VDC connected as well. Terminating resistors are fitted at both ends of this devicenet cable as this is to be my "network". The RSLinx version has the devicenet driver drop down box on the config drivers and is the newest version that works with XP and RSNetworx is V24.

When I power up the rack - the scanner does its self test - showing the major / minor revision number / speed (00 = 125k) and node 63 (default DN node address). it also shows error 72.

I can successfully set up a 1747-SDNPT driver using the ether/IP driver I have set for the 5/05 comms and this sets up without any issues. I can open RSNetworx and using the PT driver and going online in RSNetworx I can see the scanner showing up as node 63 in the graph view. So far so good... But..

I cannot for the life of me get the 1770-KFD to talk to the scanner when I set up a devicenet driver using the 1770-KFD option. With the KFD connected to the other end of my devicenet cable to the scanner, the status led is flashing green (scanner module led is flashing red). When I try to set the KFD driver all I get is a brief flash of green on the RS232 status led on the KFD convertor then nothing more.
After a short time I get the error KFD32 error stating timed out.

I've tried manually setting the 3 speeds in the 1770-KFD driver - I know the real serial port works fine and is set up within XP normally (I can set a DF1 driver up to talk to the processor instead of the Ethernet and it works fine). There is no other drivers running in RSLinx when I try to set this KFD driver up. The KFD driver is set as node 62.

What am I missing or doing wrong???. Can the 1770-KFD work directly connected to the scanner card or does it have to be in a network with other devices?. I've also tried the enabling the scanner bit in the plc output table but still nothing. I've even tried a flush of the scanner card just incase but still the same. To say i'm stumped is an understatement!!!. When you check around the issues others have had on google etc - everyone seems to be able to get the bugger to connect without any major issues.o_O

Any advice given very gratefully received!. Every days a school day!.

Bolty
 
Last edited:
he RSLinx version has the devicenet driver drop down box on the config drivers and is the newest version that works with XP

What is the actual Version Number ?

What Service Pack of Windows XP are you running ?

If you've got RSNetworx v24 installed, you almost certainly also need RSLinx 3.x as well.

The EDS management method changed after RSNetworx and Studio 5000 v21 and RSLinx 3.x were launched.

What serial cable do you have ? I've only ever successfully used the one that came with the 1770-KFD; the 1747-CP3 doesn't have the right handshaking conductors.
 
Morning Ken - thanks for reading through my long winded post.

In response to your questions, My RSLinx classic is V3.74 and XP is running with SP3.

I have only been using the serial lead supplied with the 1770-KFD. I am fortunate that I can borrow another 1770-KFD and did try this incase the one I was using was faulty but both has exactly the same effect / same symptoms so I has to be something i'm doing wrong.

I did double check the pin outs on the lead to see if they matched the pin outs given on the KFD manual for the serial lead and they were fine.

Hmm...

Bolty.
 
Well, this definitely ought to work.

I've had trouble in the past with DF1 and KF2 drivers getting in each other's way; be sure there are no DF1 drivers running and that you've done a full reboot. In fact, what you describe (setting up a DF1 driver then going to set up the KFD driver) is what I usually had to back out of and reboot after doing.

When the 1770-KFD driver goes online with the DeviceNet, it needs to verify that it's running at the appropriate data rate before it can start transmitting.

The way it does that is by transmitting a Duplicate MAC ID Check packet with its own address, at the desired data rate. That's a very short packet and shouldn't mess up a network if sent at the wrong rate. Generally, all DeviceNet nodes respond to a Duplicate MAC ID Check packet by reporting their own MAC ID. When the KFD sees those packets at the data rate it expects, it knows it can join the network.

So if you have at least one device on the network that's not set for "autobaud", then it should respond to the Duplicate MAC ID Check and the 1770-KFD ought to be able to get online.

It sounds like you've genuinely done everything right.
 
DeviceNet Principles...

**Bolty said:
...I thought it was time to get my head around some Devicenet principles...

OK, well here is one founding principle with regard DeviceNet networks...

A single DeviceNet node does not constitute a "network".

The 1747-KFD DeviceNet communications interface is not a DeviceNet node proper. It can join the "party", but it cannot start the "party". It is designed to initially interrogate an existing and active DeviceNet network before it can join using a unique node address. To interrogate for a duplicate node address it does as Ken describes - it attempts a Duplicate MAC ID Check. However, to receive a reply there must already be active communications on the wire (network) passing between at least two DeviceNet nodes.

Because there is only one DeviceNet node on the wire i.e. the 1747-SDN Scanner, there are no established communications. This is why the Scanner is showing Error 72. Its display will cycle between "63" and "72", denoting that device 63, the Scanner, is not communicating, as of course, there is currently nothing to communicate with. If all were well then the Scanner display would show "00", as I'm sure you know.

The 1747-KFD will not act as a proper node with respect to the Scanner because it is not in its scanlist. You need to add at least one other proper DeviceNet node connected and configured to the Scanner and working correctly before attempting to establish communications via the 1747-KFD.

Having said that...

There is such a thing as "single node mode" for the 1747-KFD which allows it to connect to just one DeviceNet node. This requires the addition of either a 1787-USADPTR or 1770-KFDG power supply. The 1747-KFD has a built in terminating resistor which is enabled for this mode. However, the single node which may be connected is limited to a maximum of 100mA current draw. Usually, only relatively small DeviceNet nodes would be used for this, such as sensors, etc. The 1747-SDN draws 500mA @ 5 VDC across the Backplane and draws 90 mA @ 24 VDC from the DeviceNet power supply. Although 90 mA falls under the 100 mA limit, I would still be highly doubtful that the 1747-KFD can use this single node mode with a Scanner module. I have never attempted it so it would need testing or confirmation either way from another source. I have a 1747-KFD and 1747-SDN but not the special power supplies to perform a test.

I would imagine it will be much easier for you to just add another DeviceNet node and create a valid network and then proceed from there.

Regards,
George
 
Upon further investigation, the 100mA current consumption limit for single node mode is @ 12 VDC. So it really is only intended for low power consumers.

G.
 
Morning Guys, again thanks for taking the time out to post some advice.

So from the advice given, connecting the KFD to the scanner directly, even with terminating resistors won't necessarily work and you need at least one other device in the network to create a functioning network.

I did wonder if this was the case and while I can go and connect to a live network in a plant (after I wire a drop cable from a node to provide access for the KFD) I am a little gun shy to try this before I get my head round this hence the test rig but it's looking like the only way to test it fully. I don't think I have anything that I can wire in to create a devicenet node on my test network but i'll go and see what I have hidden away.

After setting the 1747-SDNPT driver and confirmed it worked with my test rig, I am comfortable enough to do this and while this is slow, I should be able to get an upload of the current devicenet network for backup purposes using the PT driver and RSNetworx. This has been the aim of this task as I've got concerns that if one of the two scanner cards in the main plc rack went pop - we don't have the network settings saved. We have a few plants in a similar situation.

No-one else seems bothered about this happening with the usual comments of it's never failed in 15+ years but that's what worries me because it will happen one day.:unsure:

I'll use the advice given and see where it leads me.(y)

Thanks again,

Bolty.
 
Correction...

I've just realized that I had referred to the KFD interface as a 1747-KFD throughout my above post. It is, of course, a 1770-KFD. I had 1747 stuck in my head from the SDN module. I've just slapped myself on the wrist for that one.

What devices are on your live DeviceNet networks? I was of the thinking that if you have a spare scanner module then surely you would have at least one spare node device. If you are nervous about one of the scanners going faulty then perhaps you should be as nervous about one of the nodes failing? Having said that, once installed and configured well, and running in a reasonably good environment, these DeviceNet networks can chug along for donkey's years. But, you never know? If you have a number of identical or similar node devices, like drives, for instance, then I recommend you carry at least one spare.

If you cannot create a test network then I would not be too worried about attempting to connect to the live network with the 1770-KFD. You seem to understand enough to get the job done and if at all stuck then myself, Ken, or I'm sure others, are here to guide you.

I have a similar setup with two 1747-SDN modules in the one system. I have a 1770-KFD left in the door of the enclosure with a drop hanging off both networks. I can connect to either network quickly, if needs be. Last year I had to replace a faulty PowerFlex 40 with a 22-COMM-D DeviceNet adapter on one of those networks where the replacement was not a like for like swap. I got online quickly enough and, having reconfigured the drive in RSNetWorx, got the scanner updated and up and running again in no time. I would not have liked to have been relying on pass through comms to accomplish the task. It is just not as fast or reliable.

The 1747-SDNPT pass through driver is a last resort option, in my opinion, when someone either does not have an interface device, like the 1770-KFD, or cannot wire in a drop on a running network. I would not recommend you using pass through when you already have a 1770-KFD. I would get that drop wired as soon as is possible and get your interface working. Besides speed, the 1770-KFD interface is much more reliable, easier to setup (you may not think so right now) and less prone to bugs. The availability of the pass through option is very dependant on firmware revisions and software versions and which Windows OS it is run under. The M0 and M1 files for the 1747-SDN need specific expansion for the extra data required for pass through. This requires modification and download to the running system. The sucess you've had while using it on thevtest bench may not ring through to your live networks. It is doable and does work, most of the time, but there are lots of known issues using it. There are far more hurdles and potential issues involved in setting up and using pass through, for a less reliable experience.

Regards,
George
 
I'm bad for leaving posts without a conclusion so just a bit of feedback, even if it is weeks old!.

I had the opportunity to be onsite at the plant in question during a shutdown and wired in a drop cable from an easy to reach part of the DeviceNet network (using correct spec thin DN cable). I connected up the 1770-KFD, set the driver then started RSNetworx and bingo - I could see the network and take a backup..phew. This was the whole point to trying to get to grips with the 1770-KFD and experimenting on the bench beforehand.

I know now that a 1747-SDN connected to just the 1770-KFD does not work when setting the driver.

I did also try the passthru method by connecting to the DH+ at the SLC 5/04 processor and again setting the passthru driver - again this worked albeit slowly but would work to take a backup of the network.

So thanks again to those who replied and offered a few pointers - much appreciated. (y)

Bolty
 

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