When to change communicaitons settings?

[pmhamilt]

I read that the Slot Time and Max Response Delay determines the bus speed so I would assume that these parameters should be the same for all devices on the network.  Should I be concerned that these parameters are different for every vendor on this segment?  The signal looks good (O-scope, and Relcom BT3) but we are seeing some communications errors while downloading.... 

The NI Config has the following settings:

Slot Time = 8

Per DLPDU PhL Overhead = 6

Max Response Delay = 8

This Node =

This Link = 4098

Min Inter PDU Delay = 16

Time Sync Class = 3

Preamble Extension = 1

Post Trans Gap Extension = 0

Max Inter Chan Signal Skew = 0

First Unpolled Node Id = 48

Number of Consec Unpolled Nodes = 184

Looking over the devices on the network the Anderson's have the following settings:

T1 = 480,000

T2 = 2,880,000

T3 =  1,440,000

Slot Time = 3

Per DLPDU PhL Overhead = 6

Max Response Delay = 3

This Node =

This Link = 0

Min Inter PDU Delay = 3

Time Sync Class = 5

Preamble Extension = 1

Post Trans Gap Extension = 0

Max Inter Chan Signal Skew = 0

Looking over the devices on the network the Rosemount's have the following settings:

T1 = 96,000

T2 = 9,600,000

T3 =  480,000

Slot Time = 8

Per DLPDU PhL Overhead = 5

Max Response Delay = 3

This Node =

This Link = 0

Min Inter PDU Delay = 8

Time Sync Class = 4

Preamble Extension = 1

Post Trans Gap Extension = 0

Max Inter Chan Signal Skew = 0

Looking over the devices on the network the A-B FFLD has the following settings:

T1 = 480,000

T2 = 2,880,000

T3 =  1,440,000

Slot Time = 8

Per DLPDU PhL Overhead = 6

Max Response Delay = 8

This Node =

This Link = 4097

Min Inter PDU Delay = 0

Time Sync Class = 3

Preamble Extension = 1

Post Trans Gap Extension = 0

Max Inter Chan Signal Skew = 0

[fieldbus]

The default settings of network parameters recommended by FF (FF-940) are:

T1 = 480000 (15 s)

T2 = 4880000 (90 s)

T3 = 2440000 (45 s)

Time Sync Class = 1 ms
Slot Time = 8
Max Response Delay = 10
Min Inter PDU Delay = 16

Preamble Extension = 0
Post Trans Gap Extension = 0

In fact, many FF-H1 devices have their own specific settings for these parameters. Although the values are not the same, the FF-H1 communications have certain tolerance for different values. But sometimes the different settings would cause communication failure.

To understand how to set these parameters like T1 and T3, you can refer to the attached text file "t1t2t3.txt" provided by NI-FBUS software.