The Industrial Automation I/O Expansion cards for Raspberry Pi can be accessed thru Modbus RTU protocol over RS-485 port. You can set-up the RS-485 port with megaind command.
Example:
~$ megaind 0 rs485wr 1 9600 1 0 1Set Modbus RTU , Baudrate: 9600bps, 1 Stop Bit, parity: None, slave address offset: 1
~$ megaind -h rs485wrdisplay the full set of options
The slave address is add with the "stack level" jumpers. For example the jumpers configuration for stack level 1 (one jumper in position ID0) slave address offset to 1 corespond to slave address 2.
All modbus RTU object type with standard addresses are implemented : Coils, Discrete Inputs, Input registers, Holding registers.
Acces level Read/Write, Size 1 bit
| Device function | Register Address | Modbus Address |
|---|---|---|
| OPEN_DRAIN_1 | 0001 | 0x00 |
| OPEN_DRAIN_2 | 0002 | 0x01 |
| OPEN_DRAIN_3 | 0003 | 0x02 |
| OPEN_DRAIN_4 | 0004 | 0x03 |
| LED_1 | 0005 | 0x04 |
| LED_2 | 0006 | 0x05 |
| LED_3 | 0007 | 0x06 |
| LED_4 | 0008 | 0x07 |
| OPTO_RISING_COUNT_1 | 0009 | 0x08 |
| OPTO_RISING_COUNT_2 | 0010 | 0x09 |
| OPTO_RISING_COUNT_3 | 0011 | 0x0a |
| OPTO_RISING_COUNT_4 | 0012 | 0x0b |
| OPTO_FALLING_COUNT_1 | 0013 | 0x0c |
| OPTO_FALLING_COUNT_2 | 0014 | 0x0d |
| OPTO_FALLING_COUNT_3 | 0015 | 0x0e |
| OPTO_FALLING_COUNT_4 | 0016 | 0x0f |
OPTO_RISING_COUNT coil enable/disable counting on rising edge of coresponding opto channel OPTO_FALLING_COUNT coil enable/disable counting on falling edge of coresponding opto channel
Access level Read Only, Size 1 bit
| Device function | Register Address | Modbus Address |
|---|---|---|
| OPTO_1 | 10001 | 0x00 |
| OPTO_2 | 10002 | 0x01 |
| OPTO_3 | 10003 | 0x02 |
| OPTO_4 | 10004 | 0x03 |
| OWB_PRESENT | 10005 | 0x04 |
Access level Read Only, Size 16 bits
| Device function | Register Address | Description | Measurement Unit |
|---|---|---|---|
| 0-10V_IN_1 | 30001 | 0-10V Input 1 | mV |
| 0-10V_IN_2 | 30002 | 0-10V Input 2 | mV |
| 0-10V_IN_3 | 30003 | 0-10V Input 3 | mV |
| 0-10V_IN_4 | 30004 | 0-10V Input 4 | mV |
| +/-10V_IN_1 | 30005 | +/-10V Input 1 | mV |
| +/-10V_IN_2 | 30006 | +/-10V Input 2 | mV |
| +/-10V_IN_3 | 30007 | +/-10V Input 3 | mV |
| +/-10V_IN_4 | 30008 | +/-10V Input 4 | mV |
| 4-20mA_IN_1 | 30009 | 4-20mA Input 1 | uA |
| 4-20mA_IN_2 | 30010 | 4-20mA Input 2 | uA |
| 4-20mA_IN_3 | 30011 | 4-20mA Input 3 | uA |
| 4-20mA_IN_4 | 30012 | 4-20mA Input 4 | uA |
| OPTO_COUNT_1 | 30013 | Opto Count 1 | |
| OPTO_COUNT_2 | 30014 | Opto Count 2 | |
| OPTO_COUNT_3 | 30015 | Opto Count 3 | |
| OPTO_COUNT_4 | 30016 | Opto Count 4 | |
| OWB_TEMP1 | 30017 | Temperature 1 | 0.01C |
| OWB_TEMP2 | 30018 | Temperature 2 | 0.01C |
| OWB_TEMP3 | 30019 | Temperature 3 | 0.01C |
| OWB_TEMP4 | 30020 | Temperature 4 | 0.01C |
| OWB_TEMP5 | 30021 | Temperature 5 | 0.01C |
| OWB_TEMP6 | 30022 | Temperature 6 | 0.01C |
| OWB_TEMP7 | 30023 | Temperature 7 | 0.01C |
| OWB_TEMP8 | 30024 | Temperature 8 | 0.01C |
| OWB_TEMP9 | 30025 | Temperature 9 | 0.01C |
| OWB_TEMP10 | 30026 | Temperature 10 | 0.01C |
| OWB_TEMP11 | 30027 | Temperature 11 | 0.01C |
| OWB_TEMP12 | 30028 | Temperature 12 | 0.01C |
| OWB_TEMP13 | 30028 | Temperature 13 | 0.01C |
| OWB_TEMP14 | 30030 | Temperature 14 | 0.01C |
| OWB_TEMP15 | 30031 | Temperature 15 | 0.01C |
| OWB_TEMP16 | 30032 | Temperature 16 | 0.01C |
| OWB_ID_A_TEMP1 | 30033 | ID A Temperature 1 | 64 bit ID |
| OWB_ID_B_TEMP1 | 30034 | ID B Temperature 1 | |
| OWB_ID_C_TEMP1 | 30035 | ID C Temperature 1 | |
| OWB_ID_D_TEMP1 | 30036 | ID D Temperature 1 | |
| OWB_ID_A_TEMP2 | 30037 | ID A Temperature 2 | 64 bit ID |
| OWB_ID_B_TEMP2 | 30038 | ID B Temperature 2 | |
| OWB_ID_C_TEMP2 | 30039 | ID C Temperature 2 | |
| OWB_ID_D_TEMP2 | 30040 | ID D Temperature 2 | |
| OWB_ID_A_TEMP3 | 30041 | ID A Temperature 3 | 64 bit ID |
| OWB_ID_B_TEMP3 | 30042 | ID B Temperature 3 | |
| OWB_ID_C_TEMP3 | 30043 | ID C Temperature 3 | |
| OWB_ID_D_TEMP3 | 30044 | ID D Temperature 3 | |
| OWB_ID_A_TEMP4 | 30045 | ID A Temperature 4 | 64 bit ID |
| OWB_ID_B_TEMP4 | 30046 | ID B Temperature 4 | |
| OWB_ID_C_TEMP4 | 30047 | ID C Temperature 4 | |
| OWB_ID_D_TEMP4 | 30048 | ID D Temperature 4 | |
| OWB_ID_A_TEMP5 | 30049 | ID A Temperature 5 | 64 bit ID |
| OWB_ID_B_TEMP5 | 30050 | ID B Temperature 5 | |
| OWB_ID_C_TEMP5 | 30051 | ID C Temperature 5 | |
| OWB_ID_D_TEMP5 | 30052 | ID D Temperature 5 | |
| OWB_ID_A_TEMP6 | 30053 | ID A Temperature 6 | 64 bit ID |
| OWB_ID_B_TEMP6 | 30054 | ID B Temperature 6 | |
| OWB_ID_C_TEMP6 | 30055 | ID C Temperature 6 | |
| OWB_ID_D_TEMP6 | 30056 | ID D Temperature 6 | |
| OWB_ID_A_TEMP7 | 30057 | ID A Temperature 7 | 64 bit ID |
| OWB_ID_B_TEMP7 | 30058 | ID B Temperature 7 | |
| OWB_ID_C_TEMP7 | 30059 | ID C Temperature 7 | |
| OWB_ID_D_TEMP7 | 30060 | ID D Temperature 7 | |
| OWB_ID_A_TEMP8 | 30061 | ID A Temperature 8 | 64 bit ID |
| OWB_ID_B_TEMP8 | 30062 | ID B Temperature 8 | |
| OWB_ID_C_TEMP8 | 30063 | ID C Temperature 8 | |
| OWB_ID_D_TEMP8 | 30064 | ID D Temperature 8 | |
| OWB_ID_A_TEMP9 | 30065 | ID A Temperature 9 | 64 bit ID |
| OWB_ID_B_TEMP9 | 30066 | ID B Temperature 9 | |
| OWB_ID_C_TEMP9 | 30067 | ID C Temperature 9 | |
| OWB_ID_D_TEMP9 | 30068 | ID D Temperature 9 | |
| OWB_ID_A_TEMP10 | 30069 | ID A Temperature 10 | 64 bit ID |
| OWB_ID_B_TEMP10 | 30070 | ID B Temperature 10 | |
| OWB_ID_C_TEMP10 | 30071 | ID C Temperature 10 | |
| OWB_ID_D_TEMP10 | 30072 | ID D Temperature 10 | |
| OWB_ID_A_TEMP11 | 30073 | ID A Temperature 11 | 64 bit ID |
| OWB_ID_B_TEMP11 | 30074 | ID B Temperature 11 | |
| OWB_ID_C_TEMP11 | 30075 | ID C Temperature 11 | |
| OWB_ID_D_TEMP11 | 30076 | ID D Temperature 11 | |
| OWB_ID_A_TEMP12 | 30077 | ID A Temperature 12 | 64 bit ID |
| OWB_ID_B_TEMP12 | 30078 | ID B Temperature 12 | |
| OWB_ID_C_TEMP12 | 30079 | ID C Temperature 12 | |
| OWB_ID_D_TEMP12 | 30080 | ID D Temperature 12 | |
| OWB_ID_A_TEMP13 | 30081 | ID A Temperature 13 | 64 bit ID |
| OWB_ID_B_TEMP13 | 30082 | ID B Temperature 13 | |
| OWB_ID_C_TEMP13 | 30083 | ID C Temperature 13 | |
| OWB_ID_D_TEMP13 | 30084 | ID D Temperature 13 | |
| OWB_ID_A_TEMP14 | 30085 | ID A Temperature 14 | 64 bit ID |
| OWB_ID_B_TEMP14 | 30086 | ID B Temperature 14 | |
| OWB_ID_C_TEMP14 | 30087 | ID C Temperature 14 | |
| OWB_ID_D_TEMP14 | 30088 | ID D Temperature 14 | |
| OWB_ID_A_TEMP15 | 30089 | ID A Temperature 15 | 64 bit ID |
| OWB_ID_B_TEMP15 | 30090 | ID B Temperature 15 | |
| OWB_ID_C_TEMP15 | 30091 | ID C Temperature 15 | |
| OWB_ID_D_TEMP15 | 30092 | ID D Temperature 15 | |
| OWB_ID_A_TEMP16 | 30093 | ID A Temperature 16 | 64 bit ID |
| OWB_ID_B_TEMP16 | 30094 | ID B Temperature 16 | |
| OWB_ID_C_TEMP16 | 30095 | ID C Temperature 16 | |
| OWB_ID_D_TEMP16 | 30096 | ID D Temperature 16 |
Access level Read/Write, Size 16 bits
| Device function | Register Address | Modbus Address | Measurement Unit | Range |
|---|---|---|---|---|
| 0-10V_OUT_1 | 40001 | 0x00 | mV | 0..10000 |
| 0-10V_OUT_2 | 40002 | 0x01 | mV | 0..10000 |
| 0-10V_OUT_3 | 40003 | 0x02 | mV | 0..10000 |
| 0-10V_OUT_4 | 40004 | 0x03 | mV | 0..10000 |
| 4-20mA_OUT_1 | 40005 | 0x04 | uA | 4000..20000 |
| 4-20mA_OUT_2 | 40006 | 0x05 | uA | 4000..20000 |
| 4-20mA_OUT_3 | 40007 | 0x06 | uA | 4000..20000 |
| 4-20mA_OUT_4 | 40008 | 0x07 | uA | 4000..20000 |
| OPEN_DRAIN_PWM_1 | 40009 | 0x08 | 0..10000 | |
| OPEN_DRAIN_PWM_2 | 40010 | 0x09 | 0..10000 | |
| OPEN_DRAIN_PWM_3 | 40011 | 0x0a | 0..10000 | |
| OPEN_DRAIN_PWM_4 | 40012 | 0x0b | 0..10000 |
- Read Coils (0x01)
- Read Discrete Inputs (0x02)
- Read Holding Registers (0x03)
- Read Input Registers (0x04)
- Write Single Coil (0x05)
- Write Single Register (0x06)
- Write Multiple Coils (0x0f)
- Write Multiple registers (0x10)