Instruction Manual

5. Modbus RTU
63
Modbus
5.3. Data and Status Reading (Queries Using Code 03)
5.3.1 Reading Consecutive Multiple Registers
(1) Function
These registers read the contents of registers in a slave.
This function is not supported in broadcast communication.
(2) Start address list
With RC Series controllers, the sizes of send/receive buffers are set to 256 bytes, respectively.
Accordingly, a maximum of 125 registers’ worth of data consisting of 251 bytes (one register uses
two bytes), except 5 bytes (slave address + function code + number of data bytes + error check) of
the above 256 bytes, can be queried in the RTU mode. In other words, all of the data listed below
(total 21 registers) can be queried in a single communication.
It is also available to refer to multiple registers of the addresses in a row at one time of sending
and receiving.
Address [H] Symbol Name Sign Register size Byte
0500 ALA0 Alarm detail code
1 2
0501 ALA0 Alarm address
1 2
0502 - Always 0
- 1 2
0503 ALC0 Alarm code
1 2
0504,0505 ALT0 Alarm occurrence time
2 4
8400,8401 TLMC Total moving count
(Note1)
2 4
8402,8403 ODOM Total moving distance
(Note1)
2 4
841A,841B TIMN Present time(dedicated for SCON-CA)
2 4
8420,8421 TIMN
Present time
(dedicated for PCON-CA/CFA)
2 4
842E,842F TFAN
Total fan driving time
(dedicated for PCON-CFA)
2 4
9000, 9001 PNOW Current position monitor
{
2 4
9002 ALMC Present alarm code query 1 2
9003 DIPM Input port query 1 2
9004 DOPM Output port monitor query 1 2
9005 DSS1 Device status query 1 1 2
9006 DSS2 Device status query 2 1 2
9007 DSSE Expansion device status query 1 2
9008, 9009 STAT System status query 2 4
900A, 900B VNOW Current speed monitor
{
2 4
900C, 900D CNOW Current ampere monitor
{
2 4
900E, 900F DEVI Deviation monitor
{
2 4
9010, 9011 STIM System timer query 2 4
9012 SIPM Special input port query 1 2
9013 ZONS Zone status query 1 2
9014 POSS Position complete number status query 1 2
9015 SSSE Expansion system status register 1 2
901E FBFC Force feedback data monitor
{
2 4
Note 1 Dedicated for PCON-CA/CFA, SCON-CA and ERC3