Toshiba ETH-100 User Manual
32
12. Modbus TCP/IP
The ETH-100 interface supports Schneider Electric’s Modbus TCP/IP protocol,
release 1.0. The ETH-100 is conformance class 0 and partial class 1
compliant, and allows up to 8 simultaneous Modbus TCP/IP client connections
(sockets). Socket timeouts are set to 30s, which means that if a particular
open socket experiences no activity for more than 30s, then the interface
assumes that the client has experienced some sort of unexpected problem,
and the ETH-100 will close that socket.
release 1.0. The ETH-100 is conformance class 0 and partial class 1
compliant, and allows up to 8 simultaneous Modbus TCP/IP client connections
(sockets). Socket timeouts are set to 30s, which means that if a particular
open socket experiences no activity for more than 30s, then the interface
assumes that the client has experienced some sort of unexpected problem,
and the ETH-100 will close that socket.
12.1 Drive Channel Access
Each specific drive channel (Channel A, Channel B and Channel C) is
accessed via the “Unit Identifier” (UI) field of a Modbus TCP/IP packet. Drive
channel A is accessed when the UI field is set to “1”, channel B is accessed
when the UI field is set to “2”, and channel C is accessed when the UI field is
set to “3”. Any other UI setting is invalid and will result in a GATEWAY PATH
UNAVAILABLE exception (Modbus TCP/IP exception code 0A).
accessed via the “Unit Identifier” (UI) field of a Modbus TCP/IP packet. Drive
channel A is accessed when the UI field is set to “1”, channel B is accessed
when the UI field is set to “2”, and channel C is accessed when the UI field is
set to “3”. Any other UI setting is invalid and will result in a GATEWAY PATH
UNAVAILABLE exception (Modbus TCP/IP exception code 0A).
12.2 Supported Modbus Functions
The ETH-100 interface supports the Modbus TCP/IP function codes indicated
in Table 1.
in Table 1.
Table 1: Supported Modbus TCP/IP Functions
Function Code
Function
Class
3
Read multiple registers
0
6
Write single register
1
16
Write multiple registers
0
12.3 Modbus/Drive Register Mappings
The ETH-100 uses three methods to determine the manner in which Modbus
registers are mapped to ASD registers. These are outlined below.
registers are mapped to ASD registers. These are outlined below.
12.3.1 Point Mapping
The unit can contain a user-configurable point database. The point database
is a list of register mappings that describe how Modbus holding registers map
to Toshiba ASD registers. Each point in the point database contains a
“primary network number” (know as pn number in this manual), a “secondary
network number” (know as sn number in this manual), a value, and a name.
is a list of register mappings that describe how Modbus holding registers map
to Toshiba ASD registers. Each point in the point database contains a
“primary network number” (know as pn number in this manual), a “secondary
network number” (know as sn number in this manual), a value, and a name.