WI-GTWY-9-xxx Wireless Gateway V1.18
125
Modbus/TCP Addressing
The IN and OUT areas of the Ethernet interface are addressed under Modbus/TCP according to
the tables below. Since Modbus uses a 16-bit format, “Word (16-bit) Address Mode” will be
automatically applied whenever the “Modbus/TCP” checkbox is checked. If Ethernet/IP is also
enabled, the “Disable I/O Instance” option must be selected for each fieldbus mapping to which
Modbus/TCP Addressing is to apply.
IN Area Modbus TCP Addresses (WI-GTWY-9-xxx Write Locations 0 – 1023*)
Modbus Bit Address
IN
Area
Location
Modbus
Word
Address
Bit 15
Bit 14
Bit 13
---
Bit 2
Bit 1
Bit 0
0
1
1
2
3
---
14
15
16
1
2
17
18
19
---
30
31
32
---
---
---
---
---
---
---
---
---
1022
1023
16353
16354
16355
---
16382
16383
16384
1023
1024
16369
16370
16371
---
16382
16383
16384
OUT Area Modbus TCP Addresses (Fieldbus READ Locations 0 – 1023*)
Modbus Bit Address
OUT
Area
Location
Modbus
Word
Address Bit 15 Bit 14 Bit 13 ---
Bit 2
Bit 1
Bit 0
0
1025
16385
16386
16387
---
16398
16399
16400
1
1026
16401
16402
16403
---
16414
16415
16416
---
---
---
---
---
---
---
---
---
1022
2047
32737
32738
32739
---
32750
32751
32752
1023
2048
32753
32754
32755
---
32766
32767
32768
* Assumes Word Mode Addressing is selected in Configuration Software
The Fieldbus IN and OUT areas can be configured to a maximum size of 1024 words (2048
bytes) each, depending on the configured fieldbus mappings. The highest mapped location will
correspond to the highest available Modbus register (or coil) available to a Modbus/TCP client.
A Modbus/TCP client must use the appropriate Modbus Coil or Modbus Word addresses
corresponding to configuration software, as well as the correct function code (see 4.12.2
Supported Commands).