Multiprotocol Ethernet Interface User's Manual

ICC

are written via the EtherNet/IP “data table write” service. Different tags exist for

reading vs. writing.

Any given register can be accessed with its own unique tag name, or an array

tag can be used to access a group of registers with one PLC instruction. Tag

names are generated according to the following structure:

[action prefix][_reg_][register number]

Where

[action prefix] is a 2-character field, and is equal to either “rd” for read tags, or

“wr” for write tags. Although commonly followed for naming clarity, this “read

vs. write” naming convention is not strictly enforced by the interface card,

however: it is perfectly acceptable to write to a tag that starts with “rd” and read

from a tag that starts with “wr”.

[_reg_] is just the 5-character sequence “_reg_”.

[register number] is a 1- to 4-character field (“1”, “2”…”1484”, “1485”)

corresponding to the referenced register number.

Examples

Read “acceleration time 1” (register #10) ...................................rd_reg_10

Write “option frequency command” (register #1008) ..................wr_reg_1008

Read “inverter status 1” (register #1402)....................................rd_reg_1402

Additionally, a few special tags exist which provide backward-compatibility with

V1.000 network interface CPU firmware. These are specified in Table 4.

Table 4: Special Tag Reference

Service Tag Name Register Start Same As…

Data table read rd_reg_basic 1 rd_reg_1

Data table read rd_freq_out 1401 rd_reg_1401

Data table read rd_inv_stat1 1402 rd_reg_1402

Data table read rd_torq_out 1419 rd_reg_1419

Data table read rd_inv_stat2 1443 rd_reg_1443

Data table write wr_reg_basic 1 wr_reg_1

Data table write wr_cmd1 1007 wr_reg_1007

Data table write wr_freq_cmd 1008 wr_reg_1008

Data table write wr_cmd2 1024 wr_reg_1024

Data table write wr_torq_cmd 1034 wr_reg_1034

To read data from the interface card, the application PLC program must

reference a “source element” from which to start reading and the “number of

elements” to read. The “source element” will be a tag name constructed

according to the naming convention shown above, or a special tag as shown in

Table 4. The “source element” can be either a base tag (such as

“rd_reg_1301”, which starts at register 1301), or an offset from a base tag (such