// output a timed pulse coincident with rising edge of input#1 if and only if input#2 has seen a rising edge since the last pulse
// use to synchronize the output with input#1
// currently set to output BNC#3 with input#1 of BNC#1 and input#2 of backplane TTL1 
// example use case: fire laser (output) when the camera trigger is just starting (input#1) if we are ready for it (input#2)

// variables to be edited by user
outputDurationInMs = 25;  // can be no more than 16.3 seconds with normal 4kHz clock
int addrOutput = 35;  // 35 corresponds to BNC#3, change if want different output
int addrInput1 = 33;   // 33 corresponds to BNC#1, change if want different input
int addrInput2 = 42;   // 42 corresponds to TTL1 on backplane = laser shutter signal

// variables that should not need to be edited by user
// would like to define these variables as final, but this is
//  not amenable to script which can run multiple times
String plcName = "PLogic:E:36";
String propPosition = "PointerPosition";
String propCellType = "EditCellCellType";
String propCellConfig = "EditCellConfig";
String propCellInput1 = "EditCellInput1";
String propCellInput2 = "EditCellInput2";
String propCellInput3 = "EditCellInput3";
String propUpdates = "EditCellUpdateAutomatically";
String valNo = "No";
String valDFlop = "1 - D flop";
String valAND2 = "5 - 2-input AND";
String valOneShot = "14 - one shot (NRT)";
String valIOInput = "0 - input";
String valIOPushPull = "2 - output (push-pull)";
int ticsPerMs = 4;
int addrInvert= 64;
int addrEdge = 128;
int addrInput2Capture = 1;
int addrBothInputs = 2;
int addrOneShotCell = 3;


// figure out the high period in terms of PLC "tics" (4kHz)
int outputDurationTics = (int) (outputDurationInMs*ticsPerMs + 0.5);

// turn off updates to speed communication
String valUpdatesOriginal = mmc.getProperty(plcName, propUpdates);
mmc.setProperty(plcName, propUpdates, valNo);

// use D-flops to latch rising edges of two inputs
// (reset once output pulse starts)
mmc.setProperty(plcName, propPosition, addrInput2Capture);
mmc.setProperty(plcName, propCellType, valDFlop);
mmc.setProperty(plcName, propCellInput1, addrInvert);  // connect D input to logic 1
mmc.setProperty(plcName, propCellInput2, addrEdge + addrInput2);
mmc.setProperty(plcName, propCellInput3, addrEdge + addrOneShotCell);  // reset once output pulse starts

// use AND to combine edge of input#1 with latched signal from input#2
mmc.setProperty(plcName, propPosition, addrBothInputs);
mmc.setProperty(plcName, propCellType, valAND2);
mmc.setProperty(plcName, propCellInput1, addrEdge + addrInput1);
mmc.setProperty(plcName, propCellInput2, addrInput2Capture);

// use non-retriggerable one-shot to output pulse
mmc.setProperty(plcName, propPosition, addrOneShotCell);
mmc.setProperty(plcName, propCellType, valOneShot);
mmc.setProperty(plcName, propCellConfig, outputDurationTics);
mmc.setProperty(plcName, propCellInput1, addrBothInputs);
mmc.setProperty(plcName, propCellInput2, addrInvert + addrEdge);  // clock on every tic

// make sure inputs are set as inputs
mmc.setProperty(plcName, propPosition, addrInput1);
mmc.setProperty(plcName, propCellType, valIOInput);
mmc.setProperty(plcName, propPosition, addrInput2);
mmc.setProperty(plcName, propCellType, valIOInput);

// connect one shot to output and set as output
mmc.setProperty(plcName, propPosition, addrOutput);
mmc.setProperty(plcName, propCellType, valIOPushPull);
mmc.setProperty(plcName, propCellConfig, addrOneShotCell);

// restore updates
mmc.setProperty(plcName, propUpdates, valUpdatesOriginal);