6 -
8
BASE UNIT AND EXTENSION CABLE
6.
(2) When the QA1S6 B is connected between the main base unit and the QA1S5 B
(a) Selection condition
4.75VDC or higher should be supplied to the "IN" connector of the QA1S5 B in
the final extension.
(b) How to calculate voltage to "IN" connector
The 5VDC output voltage of the power supply module on the main base unit is
set to at least 4.90VDC.
Therefore, the QA1S5 B can be used if the voltage drop is 0.15VDC or lower
(4.9VDC - 4.75VDC = 0.15VDC)
The voltage supplied to the "IN" connector of the QA1S5 B reaches 4.75 VDC or higher
on the condition that the voltage drop (V) at the extension cable between the main base
unit and QA1S5 B is 0.15 VDC or lower.
[When the QA1S5 B is connected to Extension 2.]
Extension cable type
Extension cable conductor
resistance
QC05B
0.044
QC06B
0.051
QC12B
0.082
QC30B
0.172
QC50B
0.273
QC100B
0.530
Symbol
Description
V
Voltage drop at the extension cable between the main base unit and extension base unit (QA1S5 B)
In
5VDC current consumption when the extension base unit (QA1S5 B) is used as Extension n+1,
n = 1 to 6, n: Extension number of extension base unit (QA1S6 B) connected
(Sum total of current consumed by QA1S5B and currents consumed by the I/O, special function modules
loaded on the QA1S5 B.)
Rn
Extension cable resistance between the main base unit and the extension base unit (QA1S6 B) or the
extension base unit (QA1S6 B) and the extension base unit (QA1S6 B)
Rn+1
Extension cable resistance between the extension base unit (QA1S6 B) and extension base unit (QA1S5 B)
Position of extension base unit
Voltage drop caused by extension cable from the
main base unit to the QA1S5 B IN connector (V)
QA1S6 B
QA1S5 B
Extension1
Extension 2
V=(R1+R2)I1
Extension 1, Extension 2 Extension 3
V=(R1+R2+R3)I2
Extension 1 to 3
Extension 4
V=(R1+R2+R3+R4)I3
Extension 1 to 4
Extension 5
V=(R1+R2+R3+R4+R5)I4
Extension 1 to 5
Extension 6
V=(R1+R2+R3+R4+R5+R6)I5
Extension 1 to 6
Extension 7
V=(R1+R2+R3+R4+R5+R6+R7)I6
Extension
stage 1
Extension
stage 2
V
R1
R2
I1
Power
supply
module
Power
supply
module
Main base unit
Extension base unit (QA1S6 B)
Extension base unit (QA1S5 B)