Connect Tech Blue Heat/PCI PCI Serial Communications Manual De Usuario
Blue Heat/PCI User’s Manual, Connect Tech Inc.
41
Revision
0.11
Current Source/Voltage Selection
When using the current source in a loop with low resistance, the transistor will run hot. This can
be avoided by increasing the loop resistance. The calculation for Maximum Loop
Resistance(RL ) is:
When using the current source in a loop with low resistance, the transistor will run hot. This can
be avoided by increasing the loop resistance. The calculation for Maximum Loop
Resistance(RL ) is:
Where:
●
V
S
= 22V when pins 2 and 3 on jumper blocks J1, J2, J3, J4 J5, J6, J7 or J8 are jumpered
●
V
S
= 11V when pins 1 and 2 on jumper blocks J1, J2, J3, J4 J5, J6, J7 or J8 are jumpered
●
S = the number of stations in the loop (TX’s and RX’s)
●
V
D
= the voltage drop for the HP opto couplers on the SLIM. V
D
= 2.3 V for the HPCL
4100 and HPCL 4200. When you use other manufacturers’ equipment in the loop, the value
of V
of V
D
may differ.
Note:
For most applications, jumpering pins 1 and 2 on the
appropriate jumper block (J1, J2, J3, J4, J5, J6, J7 or J8) will
be satisfactory.
Jumpering pins 2 and 3 on the appropriate jumper block (J1,
J2, J3, J4, J5, J6, J7 or J8) may be required for applications
with multiple/many loads on the Current Loop network.
J1, J2, J3, J4, J5, J6, J7, and J8 are factory set with no
jumpers installed. (Please refer to
For most applications, jumpering pins 1 and 2 on the
appropriate jumper block (J1, J2, J3, J4, J5, J6, J7 or J8) will
be satisfactory.
Jumpering pins 2 and 3 on the appropriate jumper block (J1,
J2, J3, J4, J5, J6, J7 or J8) may be required for applications
with multiple/many loads on the Current Loop network.
J1, J2, J3, J4, J5, J6, J7, and J8 are factory set with no
jumpers installed. (Please refer to
J1, J2, J3, J4, J5, J6, J7, and J8)
(
)
0.020
V
S
-
V
R
Max
D
S
=
L
×