The Maximum Line Length refers to the maximum number of characters the Serial Adapter must receive before transmitting the message. The maximum value for this parameter is 1456, which corresponds to the maximum size of an Ethernet packet minus the space required for the transport layer and other head- ers.
Setting this parameter to 1 will cause the unit to transmit each character as a separate packet as soon as the unit receives it. Since there is time and memory overhead associated with send- ing each packet, it is best to keep this number as high as is reasonable for the application. However, in an environment where many packets are damaged due to some form of interfer- ence, it may be more prudent to keep this value from being set too large.
The Input Timeout specifies the length of time the Serial Adapter will wait after it has received a character before sending the accumulated characters as a packet. This value may be set to between 50 and 300,000 milliseconds. A value of 0 indicates that no input timeout is set.
The Serial Adapter allows a user to select up to four different Delimiter characters. The unit looks for the delimiters in the input stream and sends out a packet upon receipt of one of these characters. The Serial Adapter will accept any printing ASCII character (letters, numbers, or punctuation) as a delimiter, along with blank space and carriage return. Delimiter characters are transmitted with the data.
A Serial Adapter will accumulate characters until it receives a Delimiter, reaches the specified Maximum Line Length, or the length of time specified by the Input Timeout has elapsed.
When one of the these three conditions is met, the Serial Adapter will transmit the accumulated characters as a packet.
53
