Rockwell Automation 20-750-PBUS Profibus DPV1 Option Module User Manual
Page 59
Rockwell Automation Publication 750COM-UM004B-EN-P - September 2012
59
Acyclic Messaging Chapter 6
module parameters through the 20-750-PBUS option module. These are the
general formulas used to determine the slot and index numbers for a specific
parameter.
Slot Number = Base Slot Number + Quotient of (parameter number / 256)
Index Number = Remainder of (parameter number / 256)
Due to Profibus standard requirements of various identification and maintenance
functions, there is an exception to the rule for assigning
Host drive parameters.
When accessing drive parameters, the slot number will start at 0x01. This is the
formula used to determine the slot number for a
Host drive parameter.
Slot Number = Base Slot Number + Quotient of (parameter number / 256) + 1
The following examples illustrate the use of these formulas.
Example 1:
To access drive parameter 25 - [Motor NP Volts], see
to find
the slot number associated with Port 0, which can be used to access the first 256
parameters. To access parameters 257…512, the slot number will increment by 1,
and so on.
For the drive (Port 0), the base slot number is 0x00 + 1 (per the exception).
Therefore, the slot number can be calculated using the general formula:
Slot Number = 0x00 + Quotient of (25 / 256) + 1 (for Drive Host Parameters) = 0x01
The index number will be the remainder of the drive parameter number divided
by 256, as shown using this formula:
Index Number = Remainder of (25 / 256) = 25
Example 2:
To access
Device Parameter 5 - [Net Addr Cfg] in the option
module when the module is installed in drive Port 4, see
to find the Slot
Number associated with Port 4.
For Port 4
Device parameters, the base slot number is 0x50. Therefore, the slot
number can be calculated using the general formula:
Slot Number = 0x50 + Quotient of (5 / 256) = 0x50
The index number will be the remainder of the Port 4
Device parameter number
divided by 256, as shown using this formula:
Index Number = Remainder of (5 / 256) = 5
Example 3:
To access
Host Parameter 37 - [Flt Cfg Logic] in the option
module when the module is installed in drive Port 4, see
to find the Slot
Number associated with Port 4
Host Parameters.
For Port 4
Host parameters, the base slot number is 0xD0. Therefore, the slot
number can be calculated using the general formula:
Slot Number = 0xD0 + Quotient of (37 / 256) = 0xD0
The index number will be the remainder of the Port 4
Host parameter number
divided by 256, as shown using this formula:
Index Number = Remainder of (37 / 256) = 37