RIO-15C Registers
Coils (0XXXX)
| DO1 | 1 | |
| DO2 | 2 | |
| DO3 | 3 | |
| DO4 | 4 |
Discrete Inputs (1XXXX)
| DI1 | 1 | |
| DI2 | 2 | |
| DI3 | 3 | |
| DI4 | 4 |
Input Registers (3XXXX)
| ADC Channel 1 | 0=0mA, 4095=20mA | 1 |
| ADC Channel 2 | 0=0mA, 4095=20mA | 2 |
| ADC Channel 3 | 0=0mA, 4095=20mA | 3 |
| ADC Channel 4 | 0=0mA, 4095=20mA | 4 |
| Supply | 4095=FS | 5 |
| ADC Channel 1 | 0=4mA, 32767=20mA | 11 |
| ADC Channel 2 | 0=4mA, 32767=20mA | 12 |
| ADC Channel 3 | 0=4mA, 32767=20mA | 13 |
| ADC Channel 4 | 0=4mA, 32767=20mA | 14 |
| ADC Channel 1 | 0=0mA, 32767=20mA | 21 |
| ADC Channel 2 | 0=0mA, 32767=20mA | 22 |
| ADC Channel 3 | 0=0mA, 32767=20mA | 23 |
| ADC Channel 4 | 0=0mA, 32767=20mA | 24 |
| Supply | 32767=FS | 25 |
| ADC Channel 1 | 0=4mA, 4095=20mA | 31 |
| ADC Channel 2 | 0=4mA, 4095=20mA | 32 |
| ADC Channel 3 | 0=4mA, 4095=20mA | 33 |
| ADC Channel 4 | 0=4mA, 4095=20mA | 34 |
| ADC Channel 1 | raw, for cal. only | 41 |
| ADC Channel 2 | raw, for cal. only | 42 |
| ADC Channel 3 | raw, for cal. only | 43 |
| ADC Channel 4 | raw, for cal. only | 44 |
| Supply | raw, for cal. only | 45 |
Holding Registers (4XXXX)
| DI1Count | 1 | |
| DI2Count | 2 | |
| DI3Count | 3 | |
| DI4Count | 4 | |
| Debounce | in ms | 11 |
| BaudDiv | baud rate divisor | 21 |
| SerialMode | parity & stop bits | 22 |
| SerialTimeout | default=5 | 23 |
| RespDelay | in ms | 24 |
| QuietTime | in ms | 25 |
| MirSlaveTO | in s | 26 |
| MirMasterTO | in ms | 27 |
| LEDControl | 0=off, 1=on | 31 |
| MirrorMode | 0=off, 1=slave, 2=master | 32 |
| CTSEnable | 0=off, 1=on | 33 |
| MirRepeat | in s | 41 |
| MirTimeout | in s | 42 |
| MirFailSafe | bitmapped | 43 |
| MirDO1Addr | addr for DO-1 | 44 |
| MirDO2Addr | addr for DO-2 | 45 |
| MirDO3Addr | addr for DO-3 | 46 |
| MirDO4Addr | addr for DO-4 | 47 |
| MirDO1Port | port for DO-1 | 48 |
| MirDO2Port | port for DO-2 | 49 |
| MirDO3Port | port for DO-3 | 50 |
| MirDO4Port | port for DO-4 | 51 |
| MirDI1Addr | addr for DI-1 | 52 |
| MirDI2Addr | addr for DI-2 | 53 |
| MirDI3Addr | addr for DI-3 | 54 |
| MirDI4Addr | addr for DI-4 | 55 |
| MirDI1Port | port for DI-1 | 56 |
| MirDI2Port | port for DI-2 | 57 |
| MirDI3Port | port for DI-3 | 58 |
| MirDI4Port | port for DI-4 | 59 |
| MirAO1Addr | addr for AO-1 | 60 |
| MirAO2Addr | addr for AO-2 | 61 |
| MirAO1Port | port for AO-1 | 62 |
| MirAO2Port | port for AO-2 | 63 |
| MirAI1Addr | addr for AI-1 | 64 |
| MirAI2Addr | addr for AI-2 | 65 |
| MirAI3Addr | addr for AI-3 | 66 |
| MirAI4Addr | addr for AI-4 | 67 |
| MirAI1Port | port for AI-1 | 68 |
| MirAI2Port | port for AI-2 | 69 |
| MirAI3Port | port for AI-3 | 70 |
| MirAI4Port | port for AI-4 | 71 |
| DACOffset1 | signed | 81 |
| DACOffset2 | signed | 82 |
| ADCOffset1 | signed | 83 |
| ADCOffset2 | signed | 84 |
| ADCOffset3 | signed | 85 |
| ADCOffset4 | signed | 86 |
| DACScale1 | 4095=unscaled | 91 |
| DACScale2 | 4095=unscaled | 92 |
| ADCScale1 | 4095=unscaled | 93 |
| ADCScale2 | 4095=unscaled | 94 |
| ADCScale3 | 4095=unscaled | 95 |
| ADCScale4 | 4095=unscaled | 96 |
| ADCScale5 | 4095=unscaled | 97 |
| Pulse1 | in ms | 101 |
| Pulse2 | in ms | 102 |
| DAC Channel 1 | 0=4mA, 32767=20mA | 111 |
| DAC Channel 2 | 0=4mA, 32767=20mA | 112 |
| DAC Channel 1 | 0=4mA, 4095=20mA | 121 |
| DAC Channel 2 | 0=4mA, 4095=20mA | 122 |
| DAC Channel 1 | raw, for cal. only | 131 |
| DAC Channel 2 | raw, for cal. only | 132 |
| BCastReset | see below | 141-143 |
| Address | 144 | |
| DI1LongCount | 151-152 | |
| DI2LongCount | 153-154 | |
| DI3LongCount | 155-156 | |
| DI4LongCount | 157-158 | |
| SerialNum | 161-162 | |
| RadioSNum | radio serial number | 163-164 |
| LastCalTimestamp | Unix format | 171-172 |
| CalInitials | 173-174 | |
| LastUpdateTimestamp | Unix format | 175-176 |
Mirror Failsafe
Output failsafe levels are determined by the 16-bit value stored in holding register 43:
| Bits | Binary Values | Failsafe effect |
|---|---|---|
| 4, 0 | 00 10 11 |
DO-1 - no change DO-1 - OFF DO-1 - ON |
| 5, 1 | 00 10 11 |
DO-2 - no change DO-2 - OFF DO-2 - ON |
| 6, 2 | 00 10 11 |
DO-3 - no change DO-3 - OFF DO-3 - ON |
| 7, 3 | 00 10 11 |
DO-4 - no change DO-4 - OFF DO-4 - ON |
| 12, 8 | 00 10 11 |
AO-1 - no change AO-1 - LOW AO-1 - HIGH |
| 13, 9 | 00 10 11 |
AO-2 - no change AO-2 - LOW AO-2 - HIGH |
Broadcast Reset
The Modbus 
address of a RIO-15C device can be changed by broadcasting (i.e. sending to Modbus address 0) a write to holding registers 141-143.
The write should be done with a single, Write Multiple Registers command. In the first two registers (most signifigant word followed by least signifigant word), you should write the device's serial number. In the last register, you should write the new Modbus address.
As per the Modbus standard, the RIO device will not respond to this broadcast. Immediately after receipt, the RIO device will begin responding to requests made of the new address, however, this change will only be permanent if the DIP switches have all been set the same direction.
