3 - 29 3 - 29
MELSEC-Q
3 SPECIFICATIONS
3.4.14 Disconnection detection flag (Un\G49)
(1) The disconnection detection flag of the corresponding channel turns to 1 when the
disconnection of the RTD or wire break is detected.
(2) Disconnection detection availabe for conversion-enabled channels only.
(3) Disconnection is detected on each channel.
(4) The disconnection detection Signal is cleared when the Operating Condition
Setting Request (Y9) is turned on.
(5) If disconnection is detected on any of conversion-enabled channels, the
Disconnection Detection Signal (XC) also turns on.
For a channel where disconnection is detected, a value based on the Conversion
setting for disconnection detection (buffer memory address 148: Un\G148) is
stored in the CH measured temperature value (buffer memory addresses 11 to
14, 54 to 61: Un\G11 to 14, Un\G54 to 61).
Conversion of the channels not disconnected is continued.
For the Q64RD-G, "ALM LED" flashes.
b15 b14 b13 b12 b11 b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
0
0
0
0
CH4 CH3 CH2 CH1
0: Normal
1: Disconnection
0
0
0
0
0
0
0
0
(6) The relationships between disconnection detection and conversion enable/disable
are indicated below.
Connection Status
Conversion Enable/
Disable Setting
Disconnection
Detection Flag
Conversion enable
a
A
B
b
Without
disconnection
Conversion disable
OFF
Conversion enable
ON
a
A
B
b
With
disconnection
Conversion disable
OFF
Conversion enable
ON
a
A
B
b
Without
disconnection
Conversion disable
OFF
POINT
•
Any channel where no RTD is connected must be specified as "conversion
disable".
Not doing so will turn on the disconnection detection flag.
•
For temperature conversion values to be stored when the Disconnection
Detection Signal (XC) turns ON, any of "Value immediately before
disconnection", "UP scale (maximum value of measured temperature range + 5%
of measured temperature range)", "Down scale (minimum value of measured
temperature range – 5% of measured temperature range)" or "Given value" can
be selected. (Refer to Section 3.2.2.)
•
Refer to Section 4.4 for the RTD wiring.
•
Refer to Section 8.2.7 for the troubleshooting of disconnection detection.
Summary of Contents for q64rd
Page 1: ......
Page 2: ......
Page 62: ...3 39 3 39 MELSEC Q 3 SPECIFICATIONS MEMO ...
Page 92: ...5 17 5 17 MELSEC Q 5 UTILITY PACKAGE GX Configurator TI X Y Monitor Test 1 OMC refresh ...
Page 98: ...5 23 5 23 MELSEC Q 5 UTILITY PACKAGE GX Configurator TI MEMO ...
Page 175: ......
Page 176: ......