EtherCAT - Problem assigning Slaves to ECAT.IO

[Felix]

When assigning EtherCAT slaves to the ECAT.IO structure I have run into problems when the resulting IO structure has non continuous indexes. The following code fragment will result in a configuration which works perfectly. I can observe the value of ECAT[0].IO[1].Data changing as expected. However, if I change ioIndex to 10 prior to initializing the second slave, as indicated by the comment below, ECAT[0].IO[10].Data does not update.

 

 

master = 0;

ioIndex = 0;
ECAT[master].IO[ioIndex].Slave = 0;
ECAT[master].IO[ioIndex].Index = $6000
ECAT[master].IO[ioIndex].SubIndex = $1
ECAT[master].IO[ioIndex].BitLength = 16
ECAT[master].IO[ioIndex].Input = 1;


ioIndex = 1; //CHANGE THIS TO 10 for second run

i = 0;

while( i < 2)
{
	ECAT[master].IO[ioIndex].Slave = 3;
	index = $6000 + i*$10;
	ECAT[master].IO[ioIndex].Index = index;
	ECAT[master].IO[ioIndex].SubIndex = $11;
	ECAT[master].IO[ioIndex].BitLength = 32;
	ECAT[master].IO[ioIndex].Input = 1;
	ioIndex = ioIndex + 1;
	i = i + 1;
}

ECAT[master].IOCount = ioIndex;
call timer(0.1); 
ECAT[master].Enable = 1;	

 

Is it possible to assign slaves to ECAT.IO in such a manner that the resulting ECAT.IO structure is not continuous or am I missing something? I am currently working on an initialization routine for a project with about 100 EtherCAT modules and want to make sure I understand the mapping of slaves to ECAT.IO before getting too far.

 

Thank you,

Felix

[hbausley]

No it is not. The resulting ECAT.IO structure is not continuous. ECAT[master].IOcount dictates how many I/O you want serviced.