U L T R A F L E X H D P D U U S E R M A N U A L
3.9.1
SMC Interface J72
The SMC interface connector is J72 on the PDU and is a 25-pin D-sub connector. The pinout is detailed in
below. Details provided below for the 48V current monitor, 48V DC enable, and 48V DC power
fault signals.
Pin Number
Signal
Notes
1 Not-Used
2
Fan Speed Control 1
From J46 pin 4
3
PUMA ID bit
Jumper to J72 pin 4
4
Common
Jumper to J72 pin 3
5
48V current monitor
Output to SMC
6
48V current monitor return
Output to SMC
7 Not-Used
8 Not-Used
9 Not-Used
10 Not-Used
11
5V from SMC to PDU
Input from SMC
12 Not-Used
13
48V DC Enable
Input from SMC
14 Not-Used
15 Not-Used
16 Not-Used
17 Not-Used
18 Not-Used
19
48V DC power fault
Output to SMC
20
48V DC power fault return
Output to SMC
21 Not-Used
22 Not-Used
23 Not-Used
24
Fan Speed Control 1 return
From J46 pin 5
25
48V DC Enable return
Input from SMC
Table 13 – J72 Pinout
3.9.1.1
48V DC Enable
The 48V DC enable is a signal from the SMC to enable the 48V DC output. With no connections to J72, the
48V DC output will be off. To enable the 48V DC output, a 5V signal must be applied between pin 13
(positive) and pin 25 (negative) on J72. The 5V signal drives the diode side of an optocoupler to enable the
48V DC output. The 48V DC enable must be capable of providing a minimum current of 12mA to enable the
power supplies.
708401 Rev B
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