What is the consensus on the maximum number of devices that can be defined on an AS/400 twinax controller. I have always held the belief that there can only be 40 devices on a controller. We are in proces of reducing the number of controllers we have from four to two. I have found documnetation from IBM that indicates 40 devices. We did have one controller that had 43 devices defined and seemed to work fine. We have a consultant that contends that the controllers can be filled with 56 devices.
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AS/400 Twinax controller device limit 1
- Thread starter lkmalee
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- #3
gpzcrasher
Programmer
Quite right about the 56 devices.
If I remember rightly the 40 devices is a recommended maximum and going over this can potentially reduce response times.
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Rome did not create a great empire by having meetings, they did it by killing all those who opposed them.
If I remember rightly the 40 devices is a recommended maximum and going over this can potentially reduce response times.
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Rome did not create a great empire by having meetings, they did it by killing all those who opposed them.
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- #6
We have never used 5251's. Most of the terminals still in use are 3487's. The nice thing about twinax is you set one address and plug it in and you are ready to go. Try that with a PC. The answer about anything over 40 causing degredation of response times seems likely. As I said in my original post, we have had over 40 devices defined but not active. Anyway, since we are attempting to go from four to two controllers, we are heading in the right direction.
jrjuiliano
MIS
Ahhh, lovely twinax.
Suggestion if you're up for it. Instead of stringing thick twinax wire from one side of the room to another, we ended up buying a couple of Nlynx twinax hubs that work wonderfully. Best part is that if a connection gets broken with one device the entire string doesn't necessarily go down.
As far as port 0, the controller usually goes on that one. I've had nothing but problems trying to connect any other devices to that port. Maybe I just wasn't trying hard enough or something, but if this is the case by design you'd only be limited to the other ports, yes? Bringing a total of 48 (plus the one controller)?
Suggestion if you're up for it. Instead of stringing thick twinax wire from one side of the room to another, we ended up buying a couple of Nlynx twinax hubs that work wonderfully. Best part is that if a connection gets broken with one device the entire string doesn't necessarily go down.
As far as port 0, the controller usually goes on that one. I've had nothing but problems trying to connect any other devices to that port. Maybe I just wasn't trying hard enough or something, but if this is the case by design you'd only be limited to the other ports, yes? Bringing a total of 48 (plus the one controller)?
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MarkATaylor
Technical User
You can physically connect 56 devices (8 ports, 7 addresses per port) but IBM only supports 40 active devices at any one time.
I believe 'Active' is defined as attached to a job; in other words, a user signed on to a workstation, or a printer varied on with the writer started. A Sign-on screen is not considered active.
More than 40 devices in use at any one time >might< work, but I think what happens is that the job with the longest inactivity time gets ended.
I believe 'Active' is defined as attached to a job; in other words, a user signed on to a workstation, or a printer varied on with the writer started. A Sign-on screen is not considered active.
More than 40 devices in use at any one time >might< work, but I think what happens is that the job with the longest inactivity time gets ended.
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