ProSoft Technology MVI69-ADM - Manual (Page 35)

MVI-ADM ♦ 'C' Programmable Understanding the MVI-ADM API
'C' Programmable Application Development Module Developer's Guide
ProSoft Technology, Inc. Page 35 of 342
February 20, 2013
Normal Data Transfer
Normal data transfer includes the paging of the user data found in the module’s
internal database in registers 0 to 4999 and the status data. These data are
transferred through read (input image) and write (output image) blocks. The
structure and function of each block is discussed in the following topics.
Block Request from the Processor to the Module
These blocks of data transfer information from the processor to the module. The
following table describes the structure of the output image.
Offset Description Length
0 Write Block ID 1
1 to 200 Write Data 200
201 to 247 Spare 47
The Write Block ID is an index value used to determine the location in the
module’s database where the data will be placed. Each transfer can move up to
200 words (block offsets 1 to 200) of data.
Block Response from the Module to the Processor
These blocks of data transfer information from the module to the ControlLogix
processor. The following table describes the structure of the input image.
Offset Description Length
0 Reserved 1
1 Write Block ID 1
2 to 201 Read Data 200
202 Program Scan Counter 1
203 to 204 Product Code 2
205 to 206 Product Version 2
207 to 208 Operating System 2
209 to 210 Run Number 2
211 to 212 Not Used 2
213 to 219 Port 1 Error Status 7
220 to 226 Port 2 Error Status 7
227 to 232 Data Transfer Status 6
233 Port 1 Current Error/Index 1
234 Port 1 Last Error/Index 1
235 Port 2 Current Error/Index 1
236 Port 2 Last Error/Index 1
237 to 248 Spare 12
249 Read Block ID 1