E-880CM-1-E
11
5. COMMUNICATION PROCEDURE
The host system (PC, for example) sends an R/W command to a client or secondary system (EL4001).
The secondary equipment (EL4001) in turn sends a response only when the home address is in
agreement; if not, it abandons the message without sending any response. In the meantime, the host
system (PC, for example) awaits a response from a client (EL4001) after command transmission for a
predetermined time period (5 seconds or so). If no response is received within this time duration, it is
necessary for the host system (PC, etc.) to retry or other processing.
・
Normal send/receive:
・
Reception error with EL4001:
Upon detection of an error, such as command error or functional error on the EL side, a response
message with an error code is sent back to the host.
・
If communication failure occurs on the EL side or the host fails to receive a response:
Following a command transmission, the host goes into wait state. If it fails to receive a response within
a preset period of time, it retries the transmission.
Host system Command
EL4001
Response
Host system Command
EL4001
Host system Command
EL4001
Response message
is sent back with an
error code.
If no response
within a preset
period of time.
Command retransmit