ICP DAS USA I-7521 User Manual page 114

[A] Only valid when CrLf mode=4 is used.
[B] When CrLf mode is set to 4, that is no command END character, the I-752N
modules must wait for a specific time period (timeout0) without receiving any
further data in order to determine the end of the command.
RS-232: timeout1, timeout2
[A] When data is sent from the command port (RS-485) is required to be
passed to the RS-232 port, the I-752N modules will send the data to the RS-232
port and wait for a response from the RS-232 port.
(a) If no response has been received before the "timeout1" period has elapsed,
then the module will stop waiting.
(If the RS-232 port is not in wait mode and the I-752N modules
receive data from that port, the data will be sent to the buffer of that
port. The data can then be read using the "$AAU" command.)
(b) If any data is received before the timeout1 period has elapsed,
(1) If CrLf mode=0~3, any response data received will be send to the command
port (RS-485) after the I-752N modules receive the END character. However,
if the "timeout1" period elapsed and the I-752N modules still haven't
received the END character, and the "timeout2" period has elapsed without
receiving any further data, then the I-752N modules will send the received
data to the COMMAND port.
(2) If CrLf mode=4, the I-752N modules will wait for "timeout2" to elapse
without receiving any more data, then will send the received data to the
COMMAND port.
[B] "timeout1", begins when the I-752N modules start to send the bypass data to
RS-232 port, so the command transmission time from I-752n to RS-232 device
must also be considered.
[C] For "timeout2", begins at when RS-232 COM port receives one character and
restarts to count "timeout2" until next character is received.
The user must consider the buffer trigger level setting of the UART (COM1 with
only a byte buffer, COM3 or later using 16c550 with a 16 byte FIFO, the default
trigger level is set to 8. The trigger level can be set using the "$AAG1N"
command, N can be either "1," "4," "8" or "14."
The timeout1must be greater than timeout2.
[D]
I-7521/I-7522/I-7522A/I-7523/I-7524/I-7527 User's Manual,Ver2.5 Aug.2015
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