8 TROUBLESHOOTING

8.2.3 When the digital output values cannot be read

MELSEC-Q

Check item

Corrective action

Is there any fault with the analog signal lines such as

Check for faulty condition of the lines visually and perform a

disconnection?

continuity check of the signal lines.

Is the CPU module in the STOP status?

Set the CPU module to the RUN status.

 

Verify that the offset/gain settings are correct (see Sections

 

4.6, 5.6.2 and 5.6.3).

Are the offset/gain settings correct?

If the user range is being used, switch to a different default

input range and check if A/D conversion is correctly

 

 

performed. If it is correctly performed, redo the offset/gain

 

settings.

 

Check buffer memory addresses 20 and 21 (Un\G20 and

Is the input range setting correct?

Un\G21) in GX Developer system monitor.

If the input range setting is incorrect, redo the GX Developer

 

 

intelligent function module switch setting (see Section 4.5).

 

Check the ON/OFF status of the high resolution mode status

 

flag (X8) in GX Developer system monitor.

Is the resolution mode setting correct?

If the resolution mode setting is incorrect, redo the GX

 

Developer intelligent function module switch setting. (See

 

Section 4.5.)

 

Check the ON/OFF status with buffer memory 0 (Un\G0) in

Is the A/D conversion enable/disable setting for the channel

GX Developer system monitor and review the initial setting

that was input set to A/D conversion disabled?

of the sequence program or utility package (see Section

 

3.4).

 

From GX Developer, set the operating condition setting

Has the operating condition setting request (Y9) been

request (Y9) from ON to OFF, and check that the digital

output values are stored in buffer memory addresses 11 to

executed?

18 (Un\G11 to Un\G18). If so, review the initial setting of the

 

 

Sequence program or utility package (see Section 3.3).

POINT

The module may be faulty if the digital output values cannot be read after proper corrective actions have been taken according to the above check items. Consult the nearest representative or branch.

8 - 3

8 - 3

Page 117
Image 117
Mitsubishi Electronics Q68ADI When the digital output values cannot be read, 5.6.2, Flag X8 in GX Developer system monitor

Q68ADV, Q68ADI, Q64AD specifications

Mitsubishi Electronics, a renowned leader in automation technology, has developed advanced analog input modules that play a crucial role in numerous industrial applications. Among them, the Q64AD, Q68ADI, and Q68ADV models stand out with their impressive features and capabilities tailored for precise data acquisition and control.

The Q64AD module is designed for high-performance analog signal processing. It offers up to 16 channels of differential input, making it suitable for applications requiring multiple sensor readings simultaneously. The resolution of 16 bits enables accurate data capture, ensuring that subtle variations in process variables, such as temperature or pressure, are detectable. One of its key advantages is the high-speed sampling capability, allowing data collection at rates of up to 100 milliseconds per channel, essential for real-time monitoring in fast-paced environments.

In contrast, the Q68ADI model enhances the versatility of the analog input system. It includes built-in isolators, providing additional protection against noise and interference commonly found in industrial settings. This isolation feature improves the reliability of sensor readings, especially in harsh environments where electrical noise can impact performance. Furthermore, the Q68ADI supports both voltage and current input types, making it adaptable to various sensor configurations, such as thermocouples and RTDs, expanding its usability across different applications.

The Q68ADV module takes versatility a step further by integrating advanced diagnostic features. This model offers a range of additional functions, including built-in fault detection and self-diagnosis capabilities that identify issues before they escalate into significant problems. It also features temperature compensation and linearization algorithms, which enhance the accuracy of reading from thermocouples and other temperature sensors. The Q68ADV module is ideal for applications demanding high reliability and stringent performance standards, making it indispensable in industries like pharmaceuticals and food processing.

All three models are designed to seamlessly integrate with Mitsubishi's PLC systems, ensuring smooth communication and data exchange. They support various protocols, making them compatible with a wide range of devices and systems. Collectively, the Q64AD, Q68ADI, and Q68ADV modules exemplify Mitsubishi Electronics' commitment to delivering high-quality, reliable, and innovative solutions in industrial automation, empowering businesses to achieve greater efficiency and operational excellence.