The second section contains the list of NTs (Network Tags) that the system wishes either to write or read from the network. Each NT name provides an intermediate alias for a subset of the local ONSPEC data tables. Each NT consists of a 27-character name, a data type and a size. In the configuration file, the local definition of the NT for this workstation is specified, meaning that you tie the ONSPEC data table locations that are to hold the NT's values to the name.
After the keyword NTLIST is read in by the program, all the following lines will be interpreted as newly defined NTs. An error will be flagged if the data is unreadable, or if an NT is listed more than once.
The above example shows three NTs, each described on a single text line of the file. There are seven fields that must be defined.
First the name, a string of up to 27 characters that begins with an alpha character followed by alphanumeric characters, and/or underscores.
The second is the table type, or data type, of the NT. Legal entries are: EUR, EUI, FLG, EUF, EUFI, DII, DOO, SCA, OUT or STR.
The third and fourth fields are the starting and ending indices of the NT's local definition. Entries of 1 and 100 in the third and fourth fields, for example, would cause the NT to be defined as one hundred locations in size.
The fifth is the Driver flag, which indicates that if these points come in from the master, they should be sent on to the driver as well.
The sixth field controls whether or not values coming into ONSPEC from LSO should go through the historical system. If this field is set to N, the system will run faster.
The seventh field indicates to LSO whether or not this NT is initialized from this node. If this workstation has a driver attached which is reading this value, set the field to Y.
The eighth field is the GLOBAL field. This field should be set to Y if you want to share this tag with consoles connected to other masters. When set to Y all exceptions for this tag are broadcast to all masters. Any console on the network can then demand this tag from its own master.
SOURCE FIELD IN THE NTLIST
The NTLIST contains a field called SOURCE. This field can be defined as Y(es) only on one console in the entire network for each tag. This signifies that this console will supply initial values for this tag. Any console on the network can update this tag by including it in an output list.
At the master level SOURCE means that a console within the master's group supplies the initial values for the tag. When a new master checks in, it will receive initial values only from the master who has received the tag marked as source from one of its consoles.
Only the original source console can change the master's definition of the source field.
LSO will allow only one source console to initialize a network tag value, but any console can update that tag.
GLOBAL FIELD IN THE NTLIST
LSO will share data among masters only if the global field has been set to Y(es). Although this field is defined on the console, its significance is only apparent on the master.
Any console can define a tag as global but only the source console can change the master's definition. All conso
Comments can be entered in the file by placing a semi-colon (;) at the start of the comment. Comments should only be entered at the start of a line, or as the last entry on a valid line of data. Entire lines may be commented out by placing a semicolon at the start of the line.
Each line in the LSO configuration file can be no longer then 120 characters. LSO uses only the first 27 characters Network Tag names. Tags longer than 27 characters will be truncated.
NOTE: A version of the LSO program that is designated to run as a master does not need an NTLIST. Masters get all the NT configuration information from the consoles automatically at startup.