Task 2　FANUC I/O Unit Module Connection

1.2.1　FANUC PMC composition

FANUC PMC consists of built-in PMC software，interface circuit，and peripheral devices（proximity switches，solenoid valves，pressure switches，etc.）. The cable connecting the system and the subordinated I/O interface device is a high-speed serial cable called I/O Link，which is the dedicated I/O bus of FANUC. The I/O Link connection diagram is shown in Fig. 1-2-1.

In addition，I/O Link can be used to connect βi series servo amplifier and servo motor which can be used as I/O Link axis. Through RS-232C or Ethernet，FANUC system can connect to computer，diagnose and edit PMC interface status，and modify the ladder online.

1.2.2　Common I/O unit module

There are many types of I/O unit modules in FANUC system. Table 1-2-1 shows frequently-used ones.

1.2.3　Connection of I/O unit module's input and output

For various types of I/O unit module of FANUC，input and output signal connections are basically the same. The following description is divided into input and output section. The most commonly used I/O unit module is taken as an example for your information.

When connecting the input and output signals，you must pay attention that there are two kinds of the input（local）/output connection. According to current flow direction，there are source input（local）/output and leakage input（local）/output. And using which type of connection is determined by common DICOM/DOCOM of the input/output. Common I/O unit module input and output signal connection types are shown in Table 1-2-2.

I/O unit module，such as sub-line disk，can choose a group of 8-bit signal connected into a leakage or source type.

In principle，it is recommended to use sink input，which is +24 V switch input（active high）in order to avoid signal terminal ground malfunction.

For output of sub-line and other I/O unit module，source or leakage type output can be used in all conditions. Source output，that is，+24 V output，is recommended for safety. At the same time，in order to avoid short circuit，attention should be paid to polarity of freewheeling diode when connecting.

1.2.4　0i D series I/O unit module connection

0iD series I/O unit module is the most extensively used I/O unit module in CNC machine tool of FANUC system. Four 50-pin socket connections are used，which are CB104，CB105，CB106 and CB107. The input point has 96 points，and each 50-pin socket contains 24 input points which are divide into 3 bytes；the output point has 64，each 50-pin socket contains 16 output points which are divided into 2 bytes. 0i D series I/O unit module diagram and 450-pin socket specifications are shown in Table 1-2-3.

Two points need to be specially explained：

①The pin B01（+24V）of 50-pin socket（CB104，CB105，CB106，CB107）is used to input signals，which outputs DC 24V. Do not connect external 24V power to these pins.

②Each DOCOM is connected to the printed circuit board. If 50-pin socket is used to output signal（Y），make sure that DC 24V is input to the DOCOM of each 50-pin socket.

Table 1-2-3 shows that A14 pins of CB106 are defined，while other A14 pins are not defined. Leakage and source input can be chosen in CB106. Wiring method of 0i-D series I/O unit module is shown in Table 1-2-4.

In this case，a typical ZTXX30A CNC milling machine is taken as example. And the focus is I/O unit module selection and configuration methods.

In this case，the target machine tool is ZTXX30A CNC milling machine and its main specifications and parameters are shown in Table 1-2-5.

1.2.5　Training project

1. Training purpose

（1）To understand configuration of existing I/O unit module.

（2）To be able todemonstrate performances of I/O unit module configuration.

（3）To be familiar with the connection of I/O unit module.

2. Training project

Observe the configuration of training equipment and complete the form below（Table 1-2-6）.

3. Practice assessment

Observe the existing training equipment to find out which types of I/O unit modules it has，demonstrate the I/O unit module input/output points，and fill in the table 1-2-7：