TCP access and commands
The command set designed to provide consistent expansion and new features, they are sent over TCP/IP on port 17494
(0x4456). This is the default port, it can be changed in the configuration settings.
Five connections are allowed at any one time, these are independently protected but all using the same password as
defined in the board configuration.
Command
Action
dec
hex
16
0x10
Get Module Info - returns 3 bytes. Module Id (21 for ETH8020), Hardware version, Firmware
version.
32
0x20
Digital Active - follow with 1-20 to set relay on then a time for pulsed output from 1-255 (100ms
resolution) or 0 for permanent. Board will return 0 for success, 1 for failure
33
0x21
Digital Inactive - follow with 1-20 to turn relay off then a time for pulsed output from 1-255 (100ms
resolution) or 0 for permanent. Board will return 0 for success, 1 for failure
35
0x23
Digital Set Outputs - follow 3 bytes, first byte will set relays 1-8, All on = 255 (0xFF), All off = 0,
2nd byte for relays 9-16, 3rd byte for relays 17-20, Board will return 0 for success, 1 for failure
36
0x24
Digital Get Outputs - returns 3 bytes, the first corresponds with relays 1-8, 2nd byte for relays 9-16,
3rd byte for relays 17-20
37
0x25
Digital Get Inputs - returns 4 bytes, the first three bytes are always 0, the 4th bytes bits correspond
with the 8 digital inputs, a high bit meaning input is active (driven low)
50
0x32
Get Analogue Voltage - follow with 1-8 for channel and ETH8020 will respond with 2 bytes to form
an 16-bit integer (high byte first)
58
0x3A
ASCII text commands - allows a text string to switch outputs, see section below
119
0x77
Get Serial Number - Returns the unique 6 byte MAC address of the module.
120
0x78
Get Volts - returns relay supply voltage as byte, 125 being 12.5V DC
121
0x79
Password Entry - see TCP/IP password, board will return 1 for success or 2 for failure
122
0x7A
Get Unlock Time - see section below
123
0x7B
Log Out - immediately re-enables password protection,
board will return 0 for success
Digital Active/Inactive Commands
These are 3 byte commands, The first byte is the command, 32 (active means on) or 33 (inactive).
Second byte is the output number, 1-4 for the relays, or 9 - 16 for digital outputs (marked I/O1 to I/O8 on the board).
Third byte is the on time. Set this to zero for non pulsed mode, or 1-255 for a pulse in 100mS intervals (100mS to 25.5
seconds).
For example:
0x20
- turn the relay on command
0x03
- relay 3
0x32
(50) - 5 seconds (50 * 100ms)
Board will return 0 for success, 1 for failure.
Note - All bytes in a command must be sent in one TCP/IP packet . Digital outputs pull the output pin down to 0v when
active and pull up to 12v via a 10k resistor when inactive.
Analogue input read
Four analogue inputs of 0v-5v at 10-bit resolution are provided, the conversion is performed when you send the "Get
Analogue Voltage" command 0x32 and the channel number. The resulting 16 bit integer will be transmitted back in two
bytes (high byte first), combine these for the result. The 10-bit conversion will be in the lower 10 bits of the 16 bit
integer with the upper 6 bits being 0.
© Devantech Ltd 02/07/19
ETH8020 Documentation
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