Enable a Sigma controller to broadcast more than 50 globals (bit mask)

Product_Support · ‎2018-09-07

Issue

How can more than 50 globals be transmitted from a Sigma controller when there are many digital object states to share between controllers?

Product Line

Satchwell BAS & Sigma

Environment

Sigma Controller (all)

Cause

Sigma controllers are inherently limited to broadcasting a maximum of 50 global variables.

Resolution

To overcome the 50-global limit, you can encode multiple digital object states into a single analogue value using a binary count method. This allows up to 16 digital states to be represented and transmitted as one global analogue value.

This method leverages the MASK command in Sigma programmable objects to decode the analogue value back into individual digital states.

Implementation Steps

Create a Programmable Object in the Transmitting Controller

Use binary counting to combine up to 16 digital objects into a single analogue value.
Each bit in the binary representation corresponds to the on/off state of a digital object.
An analogue value of 901 represents the binary value 0000001110000101, where each bit (1 or 0) indicates the state of a digital input (DI) object.

Example:
Create a program object in the transmitting controller that 'binary' counts up to 16 digital objects:

10 XINT = 0
20 IF POINT 0|180 ON THEN XINT = XINT + 1 1st condition
30 IF POINT 0|181 ON THEN XINT = XINT + 2 2nd condition
40 IF POINT 0|182 ON THEN XINT = XINT + 4 3rd condition
50 IF POINT 0|183 ON THEN XINT = XINT + 8 4th condition
60 IF POINT 0|206 ON THEN XINT = XINT + 16 5th condition
70 IF POINT 0|207 ON THEN XINT = XINT + 32 6tht condition
80 IF POINT 0|208 ON THEN XINT = XINT + 64 7th condition
90 IF POINT 0|209 ON THEN XINT = XINT + 128 8th condition
100 IF POINT 0|210 ON THEN XINT = XINT + 256 9th condition
110 IF POINT 0|214 ON THEN XINT = XINT + 512 10th condition
120 IF POINT 0|215 ON THEN XINT = XINT + 1024 11th condition
130 IF POINT 0|216 ON THEN XINT = XINT + 2048 12th condition
140 IF POINT 0|217 ON THEN XINT = XINT + 4096 13th condition
150 IF POINT 0|218 ON THEN XINT = XINT + 8192 14th condition
160 IF POINT 0|202 ON THEN XINT = XINT + 16384 15th condition
170 IF POINT 0|203 ON THEN XINT = XINT + 32768 16th condition
180 XFLO = FLOAT ( XINT )
190 RETURN VIA TEXT 153 VALUE XFLO

Set Up Bit Masking in the Receiving Controller

In the receiving controller create up to 16 programmable objects to decode the transmitted analogue value.

Use the MASK command to extract individual digital states from the binary representation.

1st load
10 XINT = NINT POINT 0|222
20 YINT = XINT MASK ( 1 )
30 IF YINT = 1 THEN RETURN TRUE "load 1 on"
40 RETURN FALSE "load 1 off"
--------------------------------------------------------------
2nd load
10 XINT = INT POINT 0|222
20 YINT = XINT MASK ( 2 )
30 IF YINT = 2 THEN RETURN TRUE "load 2 on"
40 RETURN FALSE "load 2 off"
--------------------------------------------------------------
3rd load
10 XINT = INT POINT 0|222
20 YINT = XINT MASK ( 4 )
30 IF YINT = 4 THEN RETURN TRUE "load 3 on"
40 RETURN FALSE "load 3 off"
--------------------------------------------------------------
4th load
10 XINT = NINT POINT 0|222
20 YINT = XINT MASK ( 8 )
30 IF YINT = 8 THEN RETURN TRUE "load 4 on"
40 RETURN FALSE "load 4 off"
--------------------------------------------------------------
5th load
10 XINT = NINT POINT 0|222
20 YINT = XINT MASK ( 16 )
30 IF YINT = 16 THEN RETURN TRUE "load 5 on"
40 RETURN FALSE "load 5 off"
--------------------------------------------------------------
6th load
10 XINT = NINT POINT 0|222
20 YINT = XINT MASK ( 32 )
30 IF YINT = 32 THEN RETURN TRUE "load 6 on"
40 RETURN FALSE "load 6 off"
--------------------------------------------------------------
7th load
10 XINT = NINT POINT 0|222
20 YINT = XINT MASK ( 64 )
30 IF YINT = 64 THEN RETURN TRUE "load 7 on"
40 RETURN FALSE "load 7 off"
--------------------------------------------------------------

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