FUJI AS-Interface_What is AS-i? Checklist for Beginners

The AS-Interface is widely accepted as the industrial standard for simple I/O device connection. “Easy to learn and no wiring experience required” used in advertisement is not exaggeration at all. In other words, the real advantage of the AS-Interface lies in its simplicity.

The following 10 Qs & As shows the easiness of the AS-Interface for new users.

1.	How many inputs and outputs are required?
	The number of inputs and outputs tells you how many AS-i networks you need.

2.	How much power does the I/O require?
	The total power requirement of the respective modules determines the AS-Interface power supply capacity you need. A power supply unit satisfying power requirement must be used as power supply units cannot be connected in parallel.

3.	Are special cables required?
	Basically, any combination of flat AS-i cables or round cables can be used. Use appropriate cables out of EPDM, TPE, or PUR cables depending on ambient environmental conditions. Use repeaters or extenders when wiring distance exceeds 100m.

4.	Have the addresses been correctly assigned?
	An address allocation table should definitely be made to clarify which addresses have been assigned to which slaves. The master will not recognize double addressing as an error.

5.	How do you indicate the module addresses?
	The modules (or slaves) that are addressed, must be properly labeled.

6.	When are the modules should be installed?
	Installation shall be made after items 4. and 5. above have been completed. Cables can be freely routed.

7.	How is it all configured?
	The master read out the AS-Interface profile for each slave automatically. This also can be made using the controller software manually.

8.	How the slaves are detected?
	First you check whether the master has recognized all its slaves in configuration mode. Next you switch to operation in protect mode and switch the controller to RUN.

9.	How is testing done?
	Input/output tests are performed in the same way as the ordinary PLC method. The sensors are activated locally and then checked with the PLC.

10.	How do you start and run the system?
	You can either create your own controller software in the usual way, or use existing software. In the latter case, you might have to re-assign the addresses.