Internal User Devices - Mitsubishi Electric MELSEC-Q Series User Manual

10 DEVICES

10.2 Internal User Devices

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Internal user devices can be used for various user applications.
The "number of usable points" setting is designated in advance (default value) for
internal user devices.
However, this setting can be changed by PLC parameter device setting.
[Device setting screen]
(1) Setting range in the internal user device
For all Basic model QCPU internal user devices other than the input (X), output
(Y), step relay (S), special link relay, and special link registers (SW) devices, the
number of points used can be changed within a 16.4 k word (including 1.5k
words for an internal user device) range by PLC parameter device setting.
The items to consider when making such changes are discussed below.
(a) Setting range
1) The number of device points is designated in 16-point units.
2) A maximum of 32 k points can be designated for one type of device.
1 point is calculated as 2 points (1 for coil, 1 for contact) for the timer,
retentive timer, and counter.
(2) Memory size
Use the following formula to obtain the memory size of an internal user device.
1.5 + (Bit devices size) + (Word devices size) + (Timer, retentive timer and counter size)
(a) For bit devices:
For bit devices, 16 points are calculated as 1 word.
(Bit device size) =
(M+L+F+V+B total number of points)
16
MELSEC-Q
Default value
"Dev. point" can be changed
at devices where a "Dev. point"
value is shown in brackets.
16.4k
(Word)
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