H32B and H16B Digital input

[Dm81]

for H32B/H16B , digital input MAX 3.3V
for H32BS, digital input MAX 12v.

Hello
I tested Digital input on H32B (device is set in tcp server mode) and I received message "RELAY-ALARM-x,OK",
I have some questions: (I used a contact to test it)

•     why I receive message but after few seconds or more?
  

•     when input change status again (contact is reopen) why I don't receive a message?
  

thank you in advance