- Help Center
- Automation/Electrical
- Programmable Controllers
-
Pneumatics
- Air Cylinders
- Air Dryers
- Auto Switches
- Boosters
- Electric Actuators
- Fieldbus System/Serial Transmission System
- Fittings
- Modular F.R.L.
- Pressure Switches
- Regulators
- Rotary Actuators
- Solenoid Valve
- Temperature Control Equipment
- Vacuum Equipment
- Photoelectric Sensors
- Process Valves
- Valve Clamps and Accessories
- Pumps
- Additional Articles in Pneumatics
- Safety Valves
- Tubing
-
Hydraulics
-
Automation/Electrical
- Contact Sensors / Liquid Leakage Sensors
- Level Switches
- Basic Switches
- Limit Switches
- Push Buttons / Indicator Lamps
- Thumbwheel Switches
- Safety Limit Switches
- Temperature Controllers
- Counters
- Programmable Relays
- Programmable Controllers
- Safety Sensors
- Safety Door Switches
- Solid-state Relays
- Timers
- Inverters
- Power Supplies
- Axial Fans
- Wiring Systems
- Rotary Encoders
- Pressure Sensors
- Displacement Sensors/Measurement Sensors
- Ultrasonic Sensors
- Emergency Stop Switches
- Power Controllers
- Signal Converters
- Machine Automation Controllers
- RFID Systems
- Measuring / Motor Protective Relays
- Vision Sensors / Machine Vision Systems
- Photomicro Sensors
- Digital Panel Indicators
- Programmable Terminals
- Servomotors / Servo Drivers
- Proximity Sensors
- General Purpose Relays
- Fieldbus Communications
-
Safety
-
Website Help Center
What does it mean when the “I” or “Q” is displayed in front of a bit address in a ladder program?
CX-Programmer Ver.2.0 or higher displays "I:" and "Q:" in front of addresses in a ladder diagram to help you differentiate between inputs and outputs when reading the ladder diagram.
Note: Programmable Controllers that do not have I/O tables (i.e., CQM1H and CPM2A) do not have this feature.
When an address used in a ladder program operand is an I/O bit, and the address is allocated to a Basic I/O Unit or to a High-density I/O Unit classified as a Special I/O Unit in the I/O tables, then "I:" will be automatically added to in front of the address for real inputs, and "Q:" will be added to the front of the address for real outputs.
In CX-Programmer Ver.3.0 or higher, the "I:" and "Q:" in front of the addresses that are used to differentiate between inputs and outputs can be changed to "X:" and "Y:". The setting can be changed on the Ladder Diagram Tab Page (Tools - Options - Ladder Diagram).