BL4S200 User’s Manual
37
The BL4S200 can be used in an RS-485 multidrop network. Connect the 485+ to 485+
and 485– to 485– using single twisted-pair wires (nonstranded, tinned) as shown in
Figure 12. Note that a common ground is recommended.
Figure 12. BL4S200 Multidrop Network
The BL4S200 comes with a 220
termination resistor and two 681
bias resistors
installed and enabled with jumpers across pins 1–2 and 5–6 on header JP7, as shown in
Figure 13.
Figure 13. RS-485 Termination and Bias Resistors
RS-485
RS485+
GND
RS-485
RS485+
GND
RS-485
RS485+
GND
RESET
S1
S2
R1
CORE +3.3 V
DS1
DS2
J9
J10
J11
J12
J8
J7
J6
J5
J4
J3
J2
J1
RCM1
R7
R8
R9
R10
C63
JP4
JP5
JP6
JP3
C62
C47
JP7
RS485
JP9
JP8
KB
+5 V
GND
+3.3 v
KA
+5 V
GND
+3.3 V
C52
C55
C57
C61
C56
C60
C50 C51
C49
C59
C54
C48
C53
C58
U7
C38 C39 C40
C21
C27
C33
C17
C19
C25
C14
R4
R2
C12
C13 U5
U6
C16
C41 C42 C43
C23
C29
C35
C22
C28
C34
U8
C44 C45 C46
C24
C30
C36
R117
RP1
U4
C37
RP2
R5
R121
L2
L3
BT1
C31
C32
U3
C15
C10
U2
C11
C9
C8
U1
R116
R3
R118
C18
C20
C26
JP1
JP2
D2
D3
L1
D4
C1
C2
C3
C4
C6
TERM
TERM
KC
+5 V
GND
+3.3 V
KD
+5 V
GND
+3.3 V
CAUTION! HOT!
CAUTION! HOT!
D6
D5
D8
D7
D9
C5
C7
D10
DS4
DS3
R6
BOARD
+3.3 V
POWER
IN
RNET PWR
4
1
7
14
8
R13
R12
R11
6
10
5
6
10
5
6
10
5
2
4
3
6
10
5
D1
6
10
5
6
10
5
6
10
5
Battery
D56
D57
D58
D59
D60
J1
R1
R2
R19
R3
R4
C3
L1
C1
C2
Y1
4
1
3
R16
R17
C4
C8
C5
C6
C7
R20
U2
R21
R22
R23
C13
C12
L2
C10
JP15
C21
U7
R38
J2
R37
R36
C22
DS1
LINK
SPEED
FDX
DS3
DS2
R39
R40
R41
R35
C23
R34
U6
R33
R31
R32
D1
R66
C14
C11
C9
R7
R6
DS4
R42
J3
U18
R65
R67
R64
R29
R68
R69
R30
R24
C15 C16 R28 R27 R26
R25
C20
U5
JP12
JP13
JP14
R71
R70
R5
JP1
JP2
R72 JP3
JP4
JP5
JP6
JP7
JP8
JP9
JP10
JP11
U3 R8
R9
Q2
Q3
C91
C93
U1
R10
R1
1
R13
R12
R14
R15
C17
C18
C19
C92
C90
JP7
4
3
2
1
R12
681
W
R11
220
W
R13
681
W
485+
485
6
7
termi-
nation
bias
bias
U23
JP7
2
1
6
5
6
5
Factory
Default
electronic components distributor