GE 90-30/20/Micro manual User References, Type Description

2

User References

The data used in an application program is stored as either register or discrete references.

Table 2-3. Register References

Type

Description

%R	The prefix %R is used to assign system register references, which will store program
	data such as the results of calculations.
%AI	The prefix %AI represents an analog input register. This prefix is followed by the
	register address of the reference (for example, %AI0015). An analog input register holds the
	value of one analog input or other value.
%AQ	The prefix %AQ represents an analog output register. This prefix is followed by the
	register address of the reference (for example, %AQ0056). An analog output register holds the
	value of one analog output or other value.
	Note
	All register references are retained across a power cycle to the CPU.

Table 2-4. Discrete References

Type	Description
%I	The %I prefix represents input references. This prefix is followed by the reference’s
	address in the input table (for example, %I00121). %I references are located in the input status
	table, which stores the state of all inputs received from input modules during the last input
	scan. A reference address is assigned to discrete input modules using the configuration software
	or the Hand-Held Programmer. Until a reference address is assigned, no data will be received
	from the module. %I data can be retentive or non-retentive.
%Q	The %Q prefix represents output references. The coil check function of Logicmaster 90-
	30/20/Micro software checks for multiple uses of %Q references with relay coils or outputs on
	functions. Beginning with Release 3 of the software, you can select the level of coil checking
	desired (SINGLE, WARN MULTIPLE, or MULTIPLE). Refer to the Logicmaster 90-
	30/20Micro Programming Software User’s Manual , GFK-0466, for more information about this
	feature.
	The %Q prefix is followed by the reference’s address in the output table (for example,
	%Q00016). %Q references are located in the output status table, which stores the state of the
	output references as last set by the application program. This output status table’s values are
	sent to output modules during the output scan.
	A reference address is assigned to discrete output modules using the configuration
	software or the Hand-Held Programmer. Until a reference address is assigned, no
	data is sent to the module. A particular %Q reference may be either retentive or
	non-retentive. *
%M	The %M prefix represents internal references. The coil check function checks for multiple uses
	of %M references with relay coils or outputs on functions. Beginning with Release 3 of the
	software, you can select the level of coil checking desired (SINGLE, WARN MULTIPLE,
	or MULTIPLE). Refer to the Logicmaster 90-30/20Micro Programming Software User’s
	Manual, GFK-0466, for more information about this feature. A particular %M reference may
	be either retentive or non-retentive. *

*Retentiveness is based on the type of coil. For more information, refer to “Retentiveness of Data” on page 2-21.

2-20 Series 90-30/20/Micro Programmable Controllers Reference Manual– September 1998 GFK-0467K