MAN0974-14-EN_XL7_XL7P_UM
July 6, 2022
Page 51 | 199
CHAPTER 6:
REGISTERS
6.1
Register Definitions
When programming the XL7/XL7 PRIME OCS, data is stored in memory that is segmented into different
types. This memory in the controller is referred to as registers. Different groups of registers are defined
as either bits or words (16 bits). Multiple registers can usually be used to handle larger storage
requirements. For example, 16 single-bit registers can be used to store a word or two 16-bit registers can
be used to store a 32-bit value.
T
able 6.1 - Types of Registers found in the XL7/XL7 PRIME OCS
%AI Analog Input
16-bit input registers used to gather analog input data such as voltages,
temperatures, and speed settings coming from an attached device
%AQ Analog Output
16-bit output registers used to send analog information such a voltages, levels or
speed settings to an attached device
%D Display Bit
These are digital flags used to control the displaying of screens on a unit, which has
the ability to display a screen. If the bit is SET, the screen is displayed
%I Digital Input
Single-bit input registers. Typically, an external switch is connected to the registers
%K Key Bit
Single-bit flags used to give the programmer direct access to any front panel keys
appearing on a unit
%M Retentive Bit
Retentive single-bit registers
%Q Digital Output
Single-bit output registers. Typically, these bits are connected to an actuator,
indicator light or other physical outputs
%R General Purpose Register
Retentive 16-bit registers
%S System Bit
Single-bit bit coils predefined for system use
%SR System Register
16-bit registers predefined for system use
%T Temporary Bit
Non-retentive single-bit registers
6.2
Useful %S and %SR registers
Table 6.2
–
Common %S Register Definitions
Register
Name
Description
%S1
FST_SCN
Indicate First Scan
%S2
NET_OK
Network is OK
%S3
T_10MS
10mS timebase
%S4
T_100MS
100mS timebase
%S5
T_1SEC
1 second timebase
%S6
IO_OK
I/O is OK
%S7
ALW_ON
Always ON
%S8
ALW_OFF
Always OFF
%S9
PAUSING_SCN
Pause 'n Load soon
%S10
RESUMED_SCN
Pause 'n load done
%S11
FORCE
I/O being forced
%S12
FORCE_EN
Forcing is enabled
%S13
NET_IO_OK
Network I/O is OK
