# Does the slave respond to the master if the master send the command specifier 0x4 or 0x15 - CANopen

According to Hydac HAT 1000, if you send with the command specifier(CS) to the slave, for example 0x4 or 0x15, then the slave will not respond back. But for other command specifiers, then the slave respond back to the master.

Is that true that according to the CANopen standard, 0x4 or 0x15 as command specifier, will result that the slave won't respond back to the master?

• @jsotola Well, all LSS commands sends to all slaves and these slaves responds back. Oct 11 '21 at 17:31
• @jsotola Do you know what the real standard say? Oct 11 '21 at 17:56
• the other LSS commands are used to identify a specific slave by "asking multiple questions" ... it is unclear what would be gained by having all slaves respond to the switch mode global protocol Oct 11 '21 at 18:01
• @jsotola I assume that when the user use LSS commands, then only ONE device should be connected to the CAN network. Or else, all might get the same node ID. Oct 11 '21 at 18:04
• i searched internet for can "switch mode global" ... number of pdf documents returned ... I only read a few ... they all said something like This service is the only unacknowledged LSS service Oct 11 '21 at 18:12