Output Off-Time Current Error Detection Function - Mitsubishi Electric MELSEC iQ-R Series User Manual

1.28

Output Off-time Current Error Detection Function

Transistor output errors can be detected using this function. A current sensor (CT) for heater disconnection detection is used
to check for errors of when transistor outputs are OFF.
A heater current process value and the heater disconnection alert current value are compared. If the heater current process
value is larger than the heater disconnection alert current value, an output off-time current error occurs.
Detection of output off-time current errors is executed every 500ms. When the off time of a transistor output has been set as
follows, output off-time current errors are not detected. (CH1 Output off-time current error (Un\G401, b14) remains off.)
• When the heater disconnection judgment mode is the normal mode: 500ms or shorter
• When the heater disconnection judgment mode is the high accuracy mode: 200ms or shorter
The following shows the timing when an alert is output.
• 500ms  n
n = Value set for "Heater disconnection/output off-time current error detection delay count" of "Loop disconnection detection
setting" in "Application Setting"
When the output off-time current error status lasts longer than the time described above, the following operations are
executed:
• The HBA LED turns ON.
• 'CH1 Alert flag' (XC) turns ON.
• CH1 Output off-time current error (Un\G401, b14) is turned from ON.
• CH Output off-time current error (alarm code: 08A) is stored in 'Latest alarm code' (Un\G3).
Supported modules
• R60TCTRT2TT2BW
• R60TCRT4BW
Setting method
The setting method is the same as that for the heater disconnection detection function. ( Page 86 Heater Disconnection
Detection Function)
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1.28 Output Off-time Current Error Detection Function