RIO-8 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)

None

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

LEDControl	0=off, 1=on	31
MirrorMode	0=off, 1=slave, 2=master	32

MirRepeat	in s	41
MirTimeout	in s	42
MirFailSafe	bitmapped	43
MirDO1Addr	addr for DO1	44
MirDO2Addr	addr for DO2	45
MirDO3Addr	addr for DO3	46
MirDO4Addr	addr for DO4	47
MirDO1Port	port for DO1	48
MirDO2Port	port for DO2	49
MirDO3Port	port for DO3	50
MirDO4Port	port for DO4	51
MirDI1Addr	addr for DI1	52
MirDI2Addr	addr for DI2	53
MirDI3Addr	addr for DI3	54
MirDI4Addr	addr for DI4	55
MirDI1Port	port for DI1	56
MirDI2Port	port for DI1	57
MirDI3Port	port for DI1	58
MirDI4Port	port for DI1	59

Pulse1	in ms	61
Pulse2	in ms	62
Pulse3	in ms	63
Pulse4	in ms	64

BCastReset	see below	71-73
Address		74

DI1LongCount		81-82
DI2LongCount		83-84
DI3LongCount		85-86
DI4LongCount		87-88

SerialNum		90-91
RadioSNum	radio serial number	93-94

LastCalTimestamp	Unix format	101-102
CalInitials		103-104
LastUpdateTimestamp	Unix format	105-106

Mirror Failsafe

Output failsafe levels are determined by the 8-bit value stored in holding register 43:

Bits	Binary Values	Failsafe effect
4, 0	00 10 11	DO0 - no change DO0 - OFF DO0 - ON
5, 1	00 10 11	DO1 - no change DO1 - OFF DO1 - ON
6, 2	00 10 11	DO2 - no change DO2 - OFF DO2 - ON
7, 3	00 10 11	DO3 - no change DO3 - OFF DO3 - ON

Broadcast Reset

The Modbus address of a RIO-8 device can be changed by broadcasting (i.e. sending to Modbus address 0) a write to holding registers 71-73.

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.