HHC-N8I8OP

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Overview

Ethernet (TCP) and Modbus (RS-485) interfaced 8-channel relay output and 10 optocoupler input module.

Software

There is Chinese software to configure the MAC address, IP address, Modbus baud-rate, etc.

Configuration

Setting	Default Value
Mode	TCP Service
Destination Port	5000
Local Port	5000
Implementer Name	HHC-N8I8OP
Input Mode	Ordinary
Automatic acquisition of IP	off
Power-off preservation	off
Local IP	192.168.0.105
Subnet Mask	255.255.255.0
Gateway	192.168.0.1
Destination IP	192.168.0.101
MAC Address	485300575500
Domain Name
Serial Baud Rate	9600
Serial Parity	none
Serial Data Bits	8
Serial Stop Bits	1
Modbus TCP	off
Heartbeat Time Interval	0 seconds
Heartbeat Content	HHC-N8I8OP
Heartbeat Detection Time	0 seconds
Boot Firmware Version:	HHC-N8O8OP-V1.2-V00002
App Firmware Version:	20201231-VS0003

Modbus

Modbus TCP

By default the device has a simplistic non-Modbus plaintext "console style" protocol for querying the device. If you enable Modbus TCP mode via the configuration software, you can connect (using the same port) with Modbus TCP capable software.

Coils

The table below applies to the following Modbus function codes:

Function 01: Read Coils
Function 05: Write Single Coil

The following appears to be unsupported:

Function 15: Write Multiple Coils

Address (dec)	Description
16	Relay #1
17	Relay #2
18	Relay #3
19	Relay #4
20	Relay #5
21	Relay #6
22	Relay #7
23	Relay #8

Attempting to read addresses 0-15 or 24-128 will not give a response. Reading addresses 16-23 is known to work, though it's possible there are more valid ranges further out in the address space.

Attempting to write addresses 256-280 will not give a response. Writing addresses 0-255 are known to work, but only the range 16-23 has an understood purpose at the moment.

Discrete Inputs

Function 02: Read Discrete Inputs

Address (dec)	Description
32	Input #1
33	Input #2
34	Input #3
35	Input #4
36	Input #5
37	Input #6
38	Input #7
39	Input #8

The value returned is whether or not a logic high (+5V) is present on the input. The "+5V" and "COM" (GND / 0V) pins must be powered externally.

NOTE: A pulse (to +5V) on Input #9 is an override to turn all relays on along with a red LED, until a pulse (to +5V) on Input #10 turns them all off.

Attempting to read addresses 0-31 or 256-999 will not give a response. Reading addresses 32-255 is known to work, though it's possible there are more valid ranges further out in the address space.

Holding Registers

Function 03: Read Holding Registers
Function 06: Write Single Register
Function 16: Write Multiple Registers

Attempting to read addresses 0-330 doesn't work, but more of the address space will need to be explored.

Attempting to write addresses 0-140 doesn't work, but more of the address space will need to be explored.

Input Registers

Function 04: Read Input Registers

Attempting to read addresses 0-140 doesn't work, but more of the address space will need to be explored.

Factory Reset Button

The tactile button is hooked to pin 93 (PB7) of the microcontroller, it is used for factory reset.

Debug Interface

Header labeled "P2":

Silkscreen	MCU Pin	Function
G	GND
K	76	SWCLK/PA14
S	72	SWDIO/PA13
V	+3.3V

Bill of Materials

HHC-N8I8OP-V1.2-2019/05/03

Name	Markings
U5	AMS1117-3.3 2011
U6	M2303ADN M4776028 MPSM23
??	ST ULN2003 GO021010
??	ATMLH021 02CM CN 2021E6H
??	GigaDevice GD32F107VCT6 CEEF481 AJ2038
??	SP485EE 2027L H1PF54
??	EL817 C038
??	HanRun HR911105A 20/26
??	HUI KE HK3FF-DC5V-SHG
??	KEFA KF2EDGV/R [2-pos]
??	KEFA KF2EDGV/R [3-pos]
??	KEFA KF2EDGV/R [12-pos]