Analog RAM

The Analog RAM symbol generates analog values that are mapped to specific locations in non-volatile memory. The mapping is position-sensitive; thus if the symbol definition is altered once the SIMPL Windows program has been compiled and uploaded to the control system, this may cause the program to recall incorrect values.

In addition, it is recommended to define all NVRAM symbols at the beginning of the program. Once the program has been uploaded, if additional NVRAM symbols or modules need to be defined, these should be positioned after the previously defined NVRAM symbols.

Speed Key Names: ram, aram

Signals

Digital inputs: <store> and <recall>
Analog inputs: <ain1> through <ain999>
Digital inputs: <select1> through <select999>
For each analog input, one corresponding analog output: <aout1> through <aout999>

Description

The Analog RAM symbol stores the current values of all its analog inputs in NVRAM (non-volatile RAM) whenever the <store> input goes high while any one or more <select> inputs are high.

The stored values are recalled:

Whenever a <select> input goes high while <recall> is high;

Whenever <recall> goes high while a <select> input is high and <store> is low.

Every analog input has a corresponding analog output, and each input/output pair is independent of other input/output pairs. (In normal applications, each input/output pair will have the same signal name.)

Only one <select> input should be high when <recall> is high (thus the <select> inputs are usually routed through an Interlock symbol). This means that only one set of values can be recalled at one time. To recall a second set of values, use the Analog RAM from Database symbol, which is defined identically to Analog RAM and references the same locations in memory.

If only one <select> input is defined (there must be at least one <select> input), it can be given the signal name 1.

If <recall> is given the signal name 1, at startup the output signals will be set to the stored values that correspond to whichever <select> input is high.

If <store> and <recall> both have the signal name 1 and each analog input/output pair has the same signal name, signals will flow uninterrupted. At startup the output signals will be set to the stored values that correspond to whichever <select> input is high.