VXi VT1529A/B 사용자 설명서

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188 Creating and Running Algorithms  
Runtime Scan States
The Remote Signal Conditioning Units (RSCU) runtime scan can 
be described as being in one of the following three states: normal, 
disconnected and out of synch. In the disconnected state, the VT1422A fails 
to communicate with an RSCU for various reasons (power down, no 
connection, a malfunction in the cable, etc.). In the out of synch state, the 
RSCU channel switching multiplexer could be out of synch with the 
VT1422A due to an extra or missing trigger.
Algorithm Language
Support
Since each RSCU is connected to one of the main channels in the host 
VT1422A, the operating status of each RSCU during the scanning can be 
represented by the status of the corresponding main channel. A block of 
memory has been reserved to hold the status for each main channel that is 
connected to an RSCU. Referencing the Scan Status variable in an algorithm 
will return the operating status of the specified RSCU.
The language support for status reporting is designed as follows.
Scan status variables have the syntax S1xxS stands for Status. 1xx is the 
corresponding main channel that is connected to an RSCU. Though the 
possible range for main channels on a VT1422A is 00 to 63, not all of the 
main channels are valid for an RSCU connection. Therefore, the current 
valid range for xx is the set of discrete numbers (00, 01, 08, 09, 16, 17, 24, 
25, 32, 33, 40, 41, 48, 49, 56, 57). For example, in order to read the operating 
status of an RSCU connected to channel 24 of a VT1422A, S124 would be 
referenced in the algorithm. S1xx is treated as an input channel and can only 
be read from, not written to.
Currently, S1xx can be in one of the three states which are represented 
by 0, 1, and 2. 
S1xx is 0, when RSCU is in the normal state. 
S1xx is 1, when RSCU is in the disconnected state. 
S1xx is 2, when RSCU is in the out of synch state. 
Operating Model
Scan Status Variables are updated just after the all channels are scanned in 
the Input Phase (refer to “The Operating Sequence”). The value of the scan 
status variables is available to algorithms when they execute.