Calculation of available useful data length
This chapter informs about how to calculate the available useful data length.
Useful data length available when using LRW
Use | Frame length |
|---|---|
Ethernet frame | 1518 bytes |
Ethernet header + CRC | -18 bytes |
EtherCAT® header | -2 bytes |
Mailbox polling per LRD | -12 bytes - [≈(S/8)] bytes S = Number of slaves |
Distribution of system time and sync monitoring | -36 bytes Length independent of DC |
Monitoring of slave state | -14 bytes |
Useful data header | -12 bytes |
Available useful data | 1424 bytes - [≈(S/8)] bytes S = Number of slaves |
Available useful data when using LWR/LRD
Use | Frame length |
|---|---|
Ethernet frame | 1518 bytes |
Ethernet header + CRC | -18 bytes |
EtherCAT® header | -2 bytes |
Mailbox polling per LRD | -12 bytes - [≈(S/8)] bytes S = Number of slaves |
Distribution of system time and sync monitoring | -36 bytes Length independent of DC |
Monitoring of slave state | -14 bytes |
Useful data header | -24 bytes |
Available useful data | 1412 bytes - [≈(S/8)] bytes S = Number of slaves |
