Product : ISaGRAF V3.30

Date    : 17-November-1998

File    : ISDK_COM_Addendum.htm

Subject : Error in the IDK user's guide about ISDK_COM package

Keywords: ISDK_COM - IDK - isdk_com_send - isdk_com_ex_send


There is a mistake in the paper documentation of the ISaGRAF

IDK version 3.30 product. Error is in the description of both

isdk_com_send and isdk_com_ex_send routines.

These routines should always return TRUE, as there are some possibilities

that returning false leads the ISaGRAF communication system to be blocked

without retries.

When data cannot be sent, you still have to answer TRUE, so that the debugger

waits for the answer, and produces an error and a retry after the time-out is


Using the time-out as error detection mechanism also enables periodical retries.

Below is the correct description of isdk_com_ex_send and isdk_com_send routines

regarding their return value:

The "isdk_com_ex_send" function is called by the ISaGRAF Debugger each time a question has to be sent to the target system. The ISDK_COM software must send data and prepare the receive process, in order to catch the communication "receive" events. Below is the prototype of this function:

int FAR PASCAL isdk_com_ex_send (

HWND wParent,

LPBYTE snd_data,

WORD snd_size


The "snd_data" parameter is a far pointer to the bytes that have to be sent. The "snd_size" parameter indicates the number of bytes to be sent. It never exceed 256 characters. The "isdk_com_ex_send" function must always return TRUE whether data is correctly sent or not.


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