Hypertherm powermax65 User manual

Powermax65/85
Serial Communication Protocol
807220 – Revision 1 – January, 2011

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Overview
Both the Powermax65 and Powermax85 can support serial communications with a CNC. A five-pin serial port
sends and receives the signals over an RS-485 connection using the ModBus ASCII serial protocol. The power
supplies require both the serial port and the machine interface port (CPC connector) to be installed to provide full
communications capability. Both ports are located on the rear panel of the Powermax65 and Powermax85:
Power Supply Hardware Requirements
Machine Torch
Using the Powermax65 and Powermax85 in a mechanized application requires a machine torch. Either the M65/M85 or
M65m/M85m can be mounted to an X-Y table or other platform. See the Powermax65/Powermax85 Operator Manual
(806650) for more information on mounting a machine torch.
Communication Ports
The Powermax65 and Powermax85 may not have either the serial port or machine interface port installed at the factory.
Serial Port
To upgrade a power supply for serial communication, order the following upgrade kit and cables:
• 228539 – Includes serial interface port, internal cables, and RS-485 board.
• Serial cables:
- 223236 – RS-485 cable, unterminated, 25 ft / 7.6 m
- 223237 – RS-485 cable, unterminated, 50 ft / 15 m
- 223239 – RS-485 cable, 9-pin D-sub connector for Hypertherm controls, 25 ft / 7.6 m
- 223240 – RS-485 cable, 9-pin D-sub connector for Hypertherm controls, 50 ft / 15 m
Serial port Machine interface port
(also called a CPC
connector)

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Tx+
Tx-
Rx+
Rx-
GND
1
2
3
4
5
Serial Port Pin Assignments
The serial port on the Powermax65 and Powermax85 is a 5-pin male connector (also called a Phoenix connector). The
wiring diagram below shows the signals and show they would connect to a 9-pin connector on the CNC. The 9-pin
connector shown below is the one used on the Hypertherm EDGE Pro control. Be sure to check the serial port on your
CNC for the correct pin assignments.
If you will be using one of the unterminated serial cables (223236 or 223237) the diagram below shows the wire colors
and the signals carried on each of the wires.
1
2
3
4
6
7
8
9
5
TxD+
TxD-
RxD-
RxD+
GND
Not connected
Powermax65/85
RS-485 5-pin
serial port
CNC 9-pin serial port
or unterminated
Machine Interface Port
The machine interface port (also called a CPC connector) gives the CNC access to arc start and transfer, and to the
voltage divider. To add the machine interface port to the Powermax65 or Powermax85, order the following upgrade kit:
• 228697 – Includes machine interface port, internal cables, and voltage divider board.
• Cables:
- To use the built-in voltage divider that provides a scaled down arc voltage, in addition to signals
for arc transfer and plasma start:
- 228350 – terminated with spade (fork) connectors, 25 ft / 7.6 m
- 228351 – terminated with spade (fork) connectors, 50 ft / 15 m
- 123896 – terminated with D-sub connector (compatible with Hypertherm’s controls), 50 ft / 15 m
Not connected
Not connected
Not connected
Red
Black
Green Red
Black
White
Black
Green
White
Black

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Refer to the following diagram and table when connecting the Powermax65 or Powermax85 to a CNC with a machine
interface cable.
34
12
13
14
5
6
Signal Type Notes Connector
sockets
Cable wires
Start (start
plasma)
Input Normally open.
18 VDC open circuit voltage at
START terminals. Requires dry
contact closure to activate.
3, 4 Green, black
Transfer
(start
machine
motion)
Output Normally open. Dry contact closure
when the arc transfers.
120 VAC/1 A maximum at the
machine interface relay or switching
device (supplied by the customer).
12, 14 Red, black
Ground Ground 13
Voltage
divider
Output Divided arc signal of 20:1, 21.1:1,
30:1, 40:1, 50:1 (provides a
maximum of 18 V).
5 (-), 6 (+) Black (-), white (+)
Spade connector
- To use signals for arc transfer and plasma start only:
- 023206 – terminated with spade (fork) connectors, 25 ft / 7.6 m
- 023279 – terminated with spade (fork) connectors. 50 ft / 15 m

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
The ModBus data envelope is:
Start Address Function Data LRC End
1 character 2 characters 2 characters 0 up to 2x252 characters 2 characters 2 characters
Colon : CR/LF: 0D0A
Address The power supply address is set by the first valid ModBus message it receives from the CNC. The power
supply uses this address until it is powered down. When it is powered up again, the power supply will not have retained
the address, and will again take its address from the first valid ModBus message it receives.
Function Functions are defined in the ModBus ASCII documents referenced earlier. Examples include 04 for register
read and 06 for a single register write.
Data Includes the register location, and the data being requested from the Poiwermax or sent to the CNC.
LRC Longitudinal Redundancy Check, a method for performing a checksum on the message.
CR/LF Carriage return, line feed in hexadecimal: 0D0A. The end characters are typcially removed on incoming
messages by the CNC.
The CNC can control the following Powermax operations by writing to specific input registers, also called force
registers.
• Cut mode (normal, continuous pilot arc (CPA), gouge)
• Amperage
• Gas pressure and control mode
To put the power supply into remote control mode, the CNC needs to write to all three force registers together, once,
with correct non-zero values (see the sample command string tables later in this document). Afterward, the CNC can
write to the force registers one at a time as needed. To return the power supply to manual control, all force registers
must be set to zero.
Serial Communications with ModBus ASCII
For information on the ModBus ASCII serial protocol, please see the following documents:
• http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf
• http://www.modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
The ModBus ASCII standard defines the serial frame as:
• 19200 baud • 1start bit
• 8 data bits • 1 stop bit
• even parity
The most significant bit is the first bit and the least significant bit is the last bit.

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Last bit – Least
significant bit
(LSB)
1 bit sign
+/- at
MSB
Decimal point at
specified bit from
LSB, for example, 6
bits decimal.
87654321
First bit – Most
significant bit
(MSB)
Variable Scaling
In addition, Hypertherm uses variable scaling on some of the values as defined below:
Calculating the checksum (LRC)
ModBus ASCII requires a longitudinal redundancy check (LRC, also called a checksum) on each message.
NOTE: In the example below, and throughout this document, when you see 0x, the characters following the 0x are
hexadecimal (hex) numbers.
To calculate the LRC:
Example: :010108080001ED0D0A – the LRC is 0xED
Add the hex values of the message but exclude the start (:) and end characters (0D0A) and the LRC itself:
0x01 + 0x01 + 0x08 + 0x08 + 0x00 + 0x01 = 0x13
Subtract from 0xFF: 0xFF - 0x13 = 0xEC
Add 1: 0xEC + 0x01 = 0xED
The power supply responds to commands with either the ModBus function code and data, or with a ModBus exception
function code followed by an error code. For a list of the Modbus function and exception codes, see
http://www.modbus.org/docs/Modbus_Application_Protocol_V1_1b.pdf.
16 15 14 13 12 11 10 9
After the CNC takes control of the power supply, the switches and adjustment knob on the front panel are disabled, and
the LCD displays the remote control icon:

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Command Name Register
(Hex)
Description
cut_mode_force
Scaling is 16-bit, fixed-
point binary with 1-bit sign
at MSB and 0-bit decimal
at LSB.
0x2093 Sets the cut mode to one of these values:
Normal = 1
CPA = 2
Gouge = 3
cut_mode_force value :01062093xxxxcc
where xxxx equals the cut mode value
cc equals LRC (checksum)
Samples:
Normal :010620930001450D0A
Response: :01062093000145
CPA :010620930002440D0A
Response: :01062093000244
Gouge :010620930003430D0A
Response: :01062093000343
Sample ModBus Command String Tables
The following tables show sample command strings that could be sent from the CNC and the responses from the power
supply. The sample command strings show a single register write function. While the ModBus protocol allows you to
write to and read multiple registers, these functions are not shown in the samples.

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Command Name Register
(Hex)
Description
current_set_force
Scaling is 16-bit, fixed-point
binary with 1-bit sign at
MSB and 6 bit decimal at
LSB.
0x2094 Changes the amperage setting.
current_set_force value :01062094xxxxcc
where xxxx equals the hex value of the amperage
decimal multiplied by 64.
cc equals LRC (checksum)
Samples:
40 A
:010620940A003B0D0A
40 A × 64 = 2560 = 0xA00
Response: :010620940A003B
45 A
:0106209400B40FA0D0A
45 A × 64 = 2880 = 0x0B40
Response: :0106209400B40FA
65 A :010620941040F50D0A
65 A × 64 = 4160 = 0x1040
Response: :010620941040F5
85 A :010620941540F00D0A
85 A ×64 = 5440 = 0x1540
Response: :010620941540F0
Note: Assigning a value to current such as 55.5
follows the same equation:
55.5 A :010620940DE0580D0A
55.5 A x 64 = 3552 = 0x0DE0
Response: :010620940DE058

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POWERMAX65/85 SERIAL COMMUNICATION PROTOCOL
Command Name Register
(hex)
Description
pressure_set_force
Scaling is 16-bit, fixed-
point binary with 1-bit sign
at MSB and 7-bit decimal
at LSB.
0x2096 When pressure_set_force = 0, the gas mode is set to Automatic mode at
the power supply.
When pressure_set_force > 0, the CNC controls the gas pressure and the
pressure controls on the power supply are disabled.
pressure_set_force value :01062096xxxxcc
Where xxxx equals the hex value of the PSI decimal value multiplied by 128
cc equals LRC (checksum)
Samples:
45 PSI :010620961680AD0D0A
45 PSI × 128 = 5760 = 0x1680
Response: :010620961680AD
70 PSI :010620962300200D0A
70 PSI × 128 = 8960 = 0x2300
Response: :01062096230020
fault_code 0x2098 Reads the fault condition.
Sample: :010420980001420D0A
Response: :010402006F8A
fault_code value :010402xxxxcc
where xxxx equals the hex value of the decimal fault code
cc equals LRC (checksum)
0x006F = 111
Fault code 0-11-1 Current setting value is out of range
The full set of fault codes is shown on page 11.