Added CTUD, TP and more details for RS and SR blocks

reference/index.md

@@ -22,8 +22,8 @@ nav: start
 - [Falling Trigger (F_TRIG)](standard-function-blocks/falling-trigger)
 - [Counter Up (CTU)](standard-function-blocks/counter-up)
 - [Counter Down (CTD)](standard-function-blocks/counter-down)
-- Counter Up-Down (CTUD)
-- Timer Pulse (TP)
+- [Counter Up-Down (CTUD)](standard-function-blocks/counter-up-down)
+- [Timer Pulse (TP)](standard-function-blocks/timer-pulse)
 - [Timer On (TON)](standard-function-blocks/timer-on)
 - [Timer Off (TOF)](standard-function-blocks/timer-off)
 

reference/standard-function-blocks/counter-up-down.md

@@ -0,0 +1,14 @@
+---
+layout: inset
+title: Counter Up-Down
+---
+
+## Introduction
+
+The up-down counter can be used to both increment and decrement the same counter variable `CV`.
+A pulse on the reset input `R` resets the value of `CV` to 0. 
+A pulse on the maximum value `PV` will initialize `CV` to `PV`.
+Each time the input `CU` is set to `TRUE`, `CV` is incremented by 1, provided that `CV` is less than the maximum value `PV`.
+Each time the input `CD` is set to `TRUE`, `CV` is decremented by 1, provided that `CV` is greater than 0.
+The output `QU` is set to `TRUE` when `CV` is greater than or equal to `PV`. 
+The output `QD` is set to `TRUE` when `CV` is is less than or equal to 0. 

reference/standard-function-blocks/rs-bistable.md

@@ -8,3 +8,48 @@ title: RS Bistable
 This function block maintains its output in one of two stable states `TRUE` or `FALSE`.
 The output can be set or reset by applying a `TRUE` signal to the `Set` or `Reset` inputs.
 If both inputs are `TRUE` the output is `FALSE`.
+
+![](rs-symbol.png)
+
+## VAR_INPUT
+
+```
+VAR_INPUT
+    S  : BOOL;
+    R1 : BOOL;
+END_VAR
+```
+
+## VAR_OUTPUT
+
+```
+VAR_OUTPUT
+    Q1 : BOOL;
+END_VAR
+```
+Internal implementation:
+
+```
+Q1 := (NOT R1) AND (S OR Q1);
+```
+
+## Pinout Description
+
+| Pin Name   | Signal | Data Type | Description                                                    |
+|------------|--------|-----------|----------------------------------------------------------------|
+| `S`        | Input  | `BOOL`    | Set. This input puts the output in `TRUE` state.               |
+| `R1`       | Input  | `BOOL`    | Reset (dominant). This input puts the output in `FALSE` state. |
+| `Q1`       | Output | `BOOL`    | Q. This is the output.                                         |
+
+## Truth Table
+
+| S | R1 |  Q1            | Description                    |
+|---|----|----------------|--------------------------------|
+| 0 |  0 | Q<sub>-1</sub> | Q retains its previous state   |
+| 0 |  1 |  0             | Q is `FALSE`                   |
+| 1 |  0 |  1             | Q is `TRUE`                    |
+| 1 |  1 |  0             | Q is `FALSE`                   |
+
+## Time Diagram
+
+![](rs-time-diagram.png)

reference/standard-function-blocks/sr-bistable.md

@@ -8,3 +8,48 @@ title: SR Bistable
 This function block maintains its output in one of two stable states `TRUE` or `FALSE`.
 The output can be set or reset by applying a `TRUE` signal to the `Set` or `Reset` inputs.
 If both inputs are `TRUE` the output is `TRUE`.
+
+![](sr-symbol.png)
+
+## VAR_INPUT
+
+```
+VAR_INPUT
+    S1 : BOOL;
+    R  : BOOL;
+END_VAR
+```
+
+## VAR_OUTPUT
+
+```
+VAR_OUTPUT
+    Q1 : BOOL;
+END_VAR
+```
+Internal implementation:
+
+```
+Q1 := S1 OR ((NOT R) AND Q1);
+```
+
+## Pinout Description
+
+| Pin Name | Signal | Data Type | Description                                                    |
+|----------|--------|-----------|----------------------------------------------------------------|
+| `S`      | Input  | `BOOL`    | Set. This input puts the output in `TRUE` state.               |
+| `R1`     | Input  | `BOOL`    | Reset (dominant). This input puts the output in `FALSE` state. |
+| `Q1`     | Output | `BOOL`    | Q. This is the output.                                         |
+
+## Truth Table
+
+| S1 | R |       Q1       | Description                    |
+|----|---|----------------|--------------------------------|
+|  0 | 0 | Q<sub>-1</sub> | Q retains its previous state   |
+|  0 | 1 |        0       | Q is `FALSE`                   |
+|  1 | 0 |        1       | Q is `TRUE`                    |
+|  1 | 1 |        1       | Q is `TRUE`                    |
+
+## Time Diagram
+
+![](sr-time-diagram.png)

reference/standard-function-blocks/timer-pulse.md

@@ -0,0 +1,10 @@
+---
+layout: inset
+title: Timer Pulse
+---
+
+## Introduction
+
+The pulse timer can be used to generate pulses with a defined duration.
+If the input `IN` is set to `TRUE`, the output `Q` also becomes `TRUE` for the duration of the pulse time `PT`.
+`Q` remains `TRUE` until the current time `ET` reaches `PT`, regardless of the state of `IN`.