Configuring the Unit
4.6.10 Pack Control
Two firmware-selectable packing algorithms define how and when packets are sent to the
network. The standard algorithm is optimized for applications in which the unit is used in a
local environment, allowing for very small delays for single characters while keeping the
packet count low. The alternate packing algorithm minimizes the packet count on the
network and is especially useful in applications in a routed Wide Area Network (WAN).
Adjusting parameters in this mode can economize the network data stream.
Pack control settings are enabled in Flush Mode. Set this value to 00 if specific functions are
not needed.
Note:
See
Table 29 - Binary to Hexadecimal Conversion Table
Table 19 - Pack Control Options
Option
7
6
5
4
3
2
1
0
Idle Time
Force
transmit:
12ms
0
0
Force
transmit:
52ms
0
1
Force
transmit:
250ms
1
0
Force
transmit:
5sec
1
1
Trailing Characters
None
0 0
One
0
1
Two
1
0
Send Characters
2-Byte Send Character
Sequence
1
Send Immediately After
Send chars
1
Idle Time:
Idle time to "Force transmit" defines how long the unit should wait before sending
accumulated characters. This wait period is between characters. If there is an idle period
between characters equal to the force transmit set, then the unit will package up the serial
data currently in the buffer and send it to the network. For Alternate Packing, the default idle
time is 12ms.
Trailing Characters:
In some applications, CRC, Checksum, or other trailing characters
follow the end-of-sequence character; this option helps to adapt frame transmission to the
frame boundary.
Send Characters:
If 2-Byte Send Character Sequence is enabled, the unit interprets the
sendchars as a 2-byte sequence; if not set, they are interpreted independently.
If
Send Immediately After Characters
is not set, any characters already in the serial buffer
are included in the transmission after a "transmit" condition is found. If set, the unit sends
immediately after recognizing the transmit condition (sendchar or timeout).
Note:
A transmission might occur if status information needs to be exchanged or an
acknowledgment needs to be sent.
XPort™ User Manual and Development Kit
4-21