HID_101

When the single bit option is selected, the system will process each bit separately, as opposed to processing the entire bit combination.

In IGSS, bit patterns are read from left to right and when a raised (most significant) bit is encountered (a 1as opposed to a 0) the system will read the bit and ignore all other following bits.

Single-bit options

Single-bit options	Description
States	Select the States option to treat each state bit separately, reducing the number of states the digital object can attain.
Displays	Select the Displays option to display the state of each individual bit in the process diagram. If you select the Single bit displays option, you should not use digital template symbols as the Single-bit displays requires the diagram to display all symbols for all states of the digital object. Symbols are by default displayed by the active state in the diagram. Each raised (most significant) bit will result in the symbol defined for that bit being displayed in the diagram. For an example, each bit might represent a lamp or status light that may be either on or off.
Commands	Select the Commands option to treat each command bit separately, reducing the number of commands which the digital object can receive.

Example, Single bit for States and Displays

Three bits are used on the digital object template, which represent 8 different combinations.

In the table below, the bit patterns are shown in the left column. In the middle column we see the total number of combinations without the Single Bits option selected, and in the right column we see the total number of combinations with the Single Bits option selected.

Bit pattern in relation to mask	Single bit option not selected	Single bit option selected
000	0	0
001	1	1
010	2	2
011	3	2
100	4	3
101	5	3
110	6	3
111	7	3

Selecting one of the Single Bit options will set the system to look at each bit pattern separately, reading from left to right. When the system sees a bit that is set (a 1, most significant bit), then this bit is read and the remaining bits in the pattern are ignored.

Example, Single bit for Displays

Two bits are used on the digital object template, which represent 4 different combinations.

The digital object template does not include symbols as single-bit display digital objects should be based on non-template symbols.

A digital object is created based on the digital objects template with the single-bit display option enabled. There are two symbols defined for the two available states of the digital object, symbol (1) and symbol (2).

Bit pattern in relation to mask	Symbol displayed	Description
00	None	No symbols can be defined for the state and no symbols are displayed in the diagram.
10	(1)	The symbol (1) is displayed in the diagram.
01	(2)	The symbol (2) is displayed in the diagram.
11	(1) and (2)	Both symbols (1) and (2) are displayed in the diagram. If the Show all states option in the View menu has not been enabled and the different symbols (1) and (2) moved apart, the symbols will be displayed on top of each other, with the last symbol displayed topmost.