8
Each Rack Power unit should have their unique and own device address to communicate over the PMbus. Ex:7-bit address
setting pins are used to assign a device address for a RCP-2000 unit, as the description shows below .
A0~A4, five of the bits, can be set via a 5-pole DIP switch on the rear panel of a rack unit. The "ON" position represents
logic "0" while the "OFF" position represents logic "1".
There are 32 different addresses available to be assigned by the DIP switch. The switch settings show as below.
3.7.1 PMBus Device Addressing
1
MSB
0
A4
A3
A2
A1
A0
LSB
1 2 3 4 5
ON
Module
No.
1
1
0
16
1
17
2
18
3
19
4
20
5
21
6
22
7
23
8
24
9
25
10
26
11
27
12
28
13
29
14
30
15
31
2
2
3
3
4
4
5
5
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
Module
No.
DIP switch position
DIP switch position
Table 3-5
The RKP-CMU1 is equipped with all the PMBus commands that Rack Power needs. This makes it easy for users to monitor, manage,
and control their Rack Power systems by means of the LCD user interface or the Windows based user interface. Moreover,
the unit is compliant with PMBus Rev. 1.1 (the maximum communication speed is 100 KHz) and has the capability of identifying
up to 9 addressed units of RCP-2000.
3.7 PMBus Communication Interface
Table 3-6 shows the command list of PMBus. It is compliant with the standard protocol of PMBus Rev. 1.1. For more
detailed information, please refer to PMBus official website (http://pmbus.org/specs.html).
3.7.2 PMBus Command List
Command
Code
01h
02h
19h
20h
21h
22h
47h
79h
7Ah
# of data
Bytes
1
1
1
1
2
2
1
2
1
Description
Remote ON/OFF control
ON/OFF function configuration
Capabilities of a PMBus device
Define data format for output voltage
(format:
)
Rack power user's manual
Output voltage setting value
(format:
)
Rack power user's manual
Output voltage trimming value
(format:
)
Rack power user's manual
Define protection and response when an
output overcurrent fault occurred
Summary status reporting
Output voltage status reporting
Command
Name
OPERATION
ON_OFF_CONFIG
CAPABILITY
VOUT_MODE
VOUT_COMMAND
VOUT_TRIM
IOUT_OC_FAULT_RESPONSE
STATUS_WORD
STATUS_VOUT
Transaction
Type
R/W Byte
Read Byte
Read Byte
R Byte
R Word
R/W Word
R Byte
R Word
R Byte
46h
2
Output overcurrent setting value
(
format: Rack power user's manual)
IOUT_OC_FAULT_LIMIT
R/W Word
