Acyclic data

The ADS blocks are used to send acyclic data. These then access the PROFINET record data. So that acyclic data can be read or written, the PROFINET device must be in data exchange mode.

An ADSReadWrite is set.

ADS settings

AMSNetID: The AMSNetID of the PROFINET controller

PORT: Port number of the device (take this from the system manager)

Index GROUP: 0x0000_F823

Index OFFSET: 0x0000_0000

DATA

typedef struct {

WORD RW;

#define PN_READ 0

#define PN_WRITE 1

WORD NrOfAR;

DWORD API;

WORD Slot;

WORD SubSlot;

PNIO_RECORD RecordData;

} PNIO_CONFIGRECORD

Structure of the record data frame
nRW	nNr	nAPI	nSlot	nSubSlot	nIndex	nLen	nTrans	nReserved	Data (only write)
2 bytes	2 bytes	4 bytes	2 bytes	2 bytes	2 bytes	2 bytes	2 bytes	2 bytes	n bytes

Meaning of data from the record data frame
Designation	Values	Description
nRW	0 – READ 1 - WRITE	read- or write-access
nNr	normally „0“dec	it is possible to put multiple ARs (application releations) to one device (Controller, Supervisor, DeviceAccess). This indicates in which AR the data is exchanged -> normally there is only one AR, in this case zero.
nAPI	normally „0“dec	-> otherwise, the corresponding application profile should be placed here
nSlot	variable	Slot number
nSubSlot	variable	SubSlot number
nIndex	variable	Index number
nLen	variable	READ if nRW = 0: if the value „0“ is used when reading, the request is sent with the maximum buffer size, if nLen ≠ 0, the corresponding length is used. WRITE if nRW = 1: when writing: number of bytes, which follow from or after the “nReserved” word
nTrans	starts with „1“dec	If multiple records are downloaded at once, this transfer sequence number determines the order in which the data is processed.
nReserved	„0“dec	2 byte alignment
Data	variable	Data (from here the „nLen“ for the data length counts (writing only))

Sample:

Send a read request for I&M function 0

nRW	nNr	nAPI	InSlot	SubSlot	nIndex	nLen	nTrans	nReserved
00 00	00 00	00 00 00 00	00 00	01 00	F0 AF	00 00	01 00	00 00

Make sure that the receive data memory is large enough!