Some slave's information can not recognized

[bruce202202]

Scan output:

# ethercat slaves
0  0:0  PREOP  +  00000000
# ethercat slave -v
=== Master 0, Slave 0 ===
Device: Main
State: PREOP
Flag: +
Identity:
  Vendor Id:       0x00000000
  Product code:    0x00000000
  Revision number: 0x00000000
  Serial number:   0x00000000

Actual device information( using etherlab-1.5.2）

# ethercat slaves
0  0:0  PREOP  +  BL200EC(Modules/Slots)
# ethercat slave -v
=== Master 0, Slave 0 ===
Device: Main
State: PREOP
Flag: +
Identity:
  Vendor Id:       0x00000de7
  Product code:    0x00020310
  Revision number: 0x00010000
  Serial number:   0x00000000

SMC EX600 also has the same problem！

But slaves like Beckhoff's and WAGO‘s do not have this problem!