User`s manual

OnCell G3111/G3151/G3211/G3251 Series User’s Manual Serial Port Operation Modes
8-17
delimiter settings or when the buffer is full. When a packet length between 1 and 1024 bytes is
specified, data in the buffer will be sent as soon it reaches the specified length.
Delimiter 1 and Delimiter 2 (default=None): When Delimiter 1 is enabled, the serial port will clear
the buffer and send the data to the Ethernet port when a specific character, entered in hex format, is
received. A second delimiter character may be enabled and specified in the Delimiter 2 field, so that
both characters act as the delimiter to indicate when data should be sent.
ATTENTION
In order to enable a delimiter, packet length must be set to 0. Delimiter 2 should only be enabled
in conjunction with Delimiter 1 and never on its own; otherwise there may be data errors. Even
when a delimiter is enabled, the OnCell G3111/G3151/G3211/G3251 will still pack and send the
data when the amount of data exceeds 1 KB.
Delimiter process (default=Do Nothing): The Delimiter process field determines how the data is
handled when a delimiter is received. Delimiter 1 must be enabled for this field to have effect. If
Delimiters 1 and 2 are both enabled, both characters must be received for the delimiter process to
take place.
 Do Nothing: Data in the buffer will be transmitted when the delimiter is received.
 Delimiter + 1: Data in the buffer will be transmitted after 1 additional byte is received
following the delimiter.
 Delimiter + 2: Data in the buffer will be transmitted after 2 additional bytes are received
following the delimiter.
 Strip Delimiter: Data in the buffer is first stripped of the delimiter before being transmitted.
Force transmit (default=0 ms): This parameter defines how large a gap in serial communication the
OnCell G3111/G3151/G3211/G3251 will allow before packing the serial data in its internal buffer
for network transmission.
As data is received through the serial port, it is stored by the OnCell G3111/G3151/G3211/G3251 in
the internal buffer. The OnCell G3111/G3151/G3211/G3251 transmits data stored in the buffer via
TCP/IP, but only when the internal buffer is full or as specified by the force transmit time. When set
to 0, the force transmit time is disabled, and transmission is determined solely by the data in the
internal buffer. At 1 to 65535, the TCP/IP protocol software will pack the serial data received after
there is a gap in serial communication that exceeds the specified force transmit time.
The optimal force transmit time depends on your application, but it must be at least larger than one
character interval within the specified baudrate. For example, assume that the serial port is set to
1200 bps, 8 data bits, 1 stop bit, and no parity. In this case, the total number of bits needed to send a
character is 10 bits, and the time required to transfer one character is
(10 (bits) / 1200 (bits/s))
× 1000 (ms/s) = 8.3 ms.
Therefore, you should set the force transmit time to be larger than 8.3 ms, so in this case, it must be
greater than or equal to 10 ms.
If it is necessary to send a series of characters in the same packet, the serial device will need to send
that series of characters within the specified force transmit time, and the total length of data must be
less than or equal to the OnCell G3111/G3151/G3211/G3251’s internal buffer size (1 KB per port).