
Stride Field I/O
1
SIO-MB08ADS-1 User Guide, 1st Edition
GENERAL DESCRIPTION
Modbus data is mapped in tables and assigned an address. Data can be of two types:
• REGISTER, 2 bytes (word of 16 bits) that can be associated to an analog input or output, a variable, a setpoint, etc.
• COIL, 1 bit that can be associated to a digital input or output, or to a logic state.
A register could contain the image (mirror) of a group of coils; for example, the system flags of the device could be read or written
as individual bits addressing the coil related to each or can be read or written as a word addressing the register. Modbus registers and
coils are divided into the following groups of addresses:
• 0xxxx and 1xxxx = Coils (bit)
• 3xxxx and 4xxxx = Registers (word)
When reading functions are performed, use the tables indicated below to address the registers. These registers may be addressed by a
Modbus TCP/IP server or by the integrated web server.
COIL ADDRESSES
Coil (Hex) Coil (Dec) Description Access
0x00A1 00161 Watchdog Enable R/W
0x00A2 00162 Watchdog Event R/W
0x00A3 00163 Power Up Event R/W
REGISTER ADDRESSES
Register Description Access
40002 Firmware [0] RO
40003 Firmware [1] RO
40004 -Reserved- RO
40005 -Reserved- RO
40007 Node ID R/W
40011 System Flags R/W
40013 Watchdog timer R/W
40031 Input Type, Channels 1–0 R/W
40032 Input Type, Channels 3–2 R/W
40033 Input Type, Channels 5–4 R/W
40034 Input Type, Channels 7–6 R/W
40041 Analog Input (0) - Ch0 RO
40042 Analog Input (1) - Ch1 RO
40043 Analog Input (2) - Ch2 RO
40044 Analog Input (3) - Ch3 RO
40045 Analog Input (4) - Ch4 RO
40046 Analog Input (5) - Ch5 RO
40047 Analog Input (6) - Ch6 RO
40048 Analog Input (7) - Ch7 RO
SUPPORTED MODBUS FUNCTION CODES
Function Description
01 Read Coil Status (0xxxx)
02 Read Inputs Status (1xxxx)
03 Read Holding Registers (4xxxx)
04 Read Inputs Registers (3xxxx)
05 Force Single Coil
06 Preset Single Register
15 (0x0F) Force Multiple Coils
16 (0x10) Preset Multiple Registers
NOTES:
• Registers and coils marked as RO in the column ‘Access’ are Read Only registers.
• Registers and coils marked as R/W in the column ‘Access’ are Read and Write registers.
• The group of 0xxxx addresses mirrors the group of 1xxxx addresses; the group of 3xxxx addresses mirrors the 4xxxx addresses.
Therefore the first register could be addressed either as 30002 (with function 04) or 40002 ( with function 03).
• A maximum of
128 coils can be read through Modbus function codes 01 and 02 (see “Supported modbus functions codes”).
• A maximum of 64 registers can be read through Modbus function codes 03 and 04 (see “Supported modbus functions codes”).
• A maximum of
64 registers can be written by Modbus function code 16 (see “Supported modbus functions codes”).
• A maximum of
64 coils can be written by Modbus function code 15 (see “Supported modbus functions codes”).