6 BASE UNIT AND EXTENSION CABLE
6.6 Guideline for Use of Extension Base Units (Q5B)
Since the Q5B is supplied with 5VDC from the power supply module on the main base unit, a voltage drop occurs at extension cables.
Improper I/O may be provided if the specified voltage (4.75VDC or higher) is not supplied to the "IN" connector of the Q5B.
When using the Q5B, make sure that the "IN" connector of the Q5B is supplied with 4.75VDC or higher.
And it is recommend to connect it with the shortest possible extension cable right after connecting the main base unit, so as to minimize the effects of voltage drop.
(1)When only the Q5B is connected to the extension base unit
(a)Selection condition
4.75VDC or higher should be supplied to the "IN" connector of the Q5B in the final extension stage.
(b) How to calculate voltage to "IN" connector
V1 R1
V2 R2
R7 R7
The 5VDC output voltage of the power supply module on the main base unit is set to at least 4.90VDC.
Therefore, the Q5B can be used if the voltage drop is 0.15VDC or lower (4.9VDC - 4.75VDC = 0.15VDC).
| Main base unit (Q3 B) |
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| Extension Cable | |
Power |
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| Extension Cable | ||
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| Conductor | |||
supply |
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| Type | ||
module |
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| Resistance ( ) | ||
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Extension base unit (Q5 | B) | QC05B | 0.044 | ||
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| Extension stage 1 | QC06B | 0.051 |
l1 |
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| QC12B | 0.082 | |
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| QC30B | 0.172 |
Extension base unit (Q5 | B) | QC50B | 0.273 | ||
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l2 |
| Extension stage 2 | QC100B | 0.530 | |
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Extension base unit (Q5
B)
Extension stage 7
l7
Symbol | Description | |
V1 | Voltage drop at the extension cable between the main base unit and extension base unit | |
Vn | Voltage drop at the extension cable between the extension base unit (extension stage | |
unit (extension stage n) | ||
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R1 | Cable resistance between the main base unit and extension base unit | |
Rn | Cable resistance between the extension base unit (extension stage | |
stage n) | ||
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l1 to l7 | 5VDC current consumption among extension stage 1 to 7 1 |
1: Sum total of current consumed by Q5B and currents consumed by the I/O, intelligent function modules loaded on the Q5B.
The symbols including "I" (I1 to I7) vary with the modules loaded on the extension base unit. For details of the symbol, refer to the user's manuals of the module used.
6 - 8 | 6 - 8 |