Cascade Driver Specifications

Cogent API and Utilities: Version 4.1
Prev |  | Next

# Chapter 7. Cascade Driver Specifications

The Cascade Driver API functions can be grouped according to their purpose, as follows:

### Connection and Command Functions

DR_ApInitIPC
DR_ApConnectIPC
DR_ApCloseIPC
DR_ApCommand

### Point Interface

DR_ApReadPoint
DR_ApWritePoint
DR_ApListPoints
DR_ApDescribePnt
DR_ApPointBufAddress

### Block Interface

DR_ApReadBlock
DR_ApWriteBlock
DR_ApListBuffers
DR_ApDescribeBuffer
DR_ApUpdateBuffers
DR_ApReadStatus
DR_ApReadControl
DR_ApWriteControl

All these functions are described in detail in the Reference. They are intended to be quite generic, to provide a consistent interface for different types of cards. However there are some exceptions for specific drivers, which are discussed in this chapter.

# 7.1. Hilscher Fieldbus CIF Card block functions

The CIF card defines specific buffers and block lengths for block functions where valid data is available, as follows:

- The DR_ApReadBlock and DR_ApWriteBlock functions access the process I/O data area of the card. The offset and size parameters specify what portion of the buffer area to transfer, and is dependent on the field configuration. Typically, field data is always mapped to the beginning of the block (offset of `0`) and is continguous up to the number of bytes defined by the field device (slave) configuration. The output process data buffer is mapped as buffer `0`, while `1` will access the input process data buffer.

- The DR_ApReadControl and DR_ApWriteControl functions access the control parameter blocks of the card. Only buffer 2 is valid for CIF cards, which provides access to the protocol parameters. See the Hilscher Fieldbus Card Control API section for details.

- The DR_ApReadStatus function accesses the status blocks of the card. Only buffer `2` is valid for CIF cards, which provides master status as well as field device (slave) status and diagnostic information. See the Hilscher Fieldbus Card Status API section for details.

Prev | Home | Next
Binary Data Buffer Functions | Up | Hilscher Fieldbus CIF Card Control API

Copyright 1995-2002 by Cogent Real-Time Systems, Inc.