GW-7553-B / GW-7553-M PROFIBUS/Modbus TCP Gateway User Manual
(Version 1.35, May/2017)
PAGE: 30
DP-V1 services supported by GW-7553-B / GW-7553-M are Read
、
Write and
Data Transport service, Alarm_Ack didn‟t supported. List shown below is the
Slot-Index mapping table.
Table 13 Slot-Index mapping table
Slot
Modbus Type
Index
Length
1
N/A
0
1
2~32
RDI
NO. of relay/Coil
1
RDO
WDO
RAI
NO. of Words
2
RAO
WAO
33~255
N/A
N/A
N/A
Slot 1
is used for the system setting module. Because the user must add “System
setting module” at the first module before the other modules, else the GW-7553-B
/ GW-7553-M will send the diagnostic messages to PROFIBUS Master and the
system will be abnormal.
Slot 2~32
is used for Modbus modules. Index mapped input/output channel from
corresponding module. If a digital module(DI/DO module), one index is only one
bit. If an analog module(AI/AO module), one index is one word.
Slot 33~255
is not supported by GW-7553-B / GW-7553-M. Because the
maximum number of I/O modules is 32.
Note
：
The data block fixed by DPV1 write acyclic service will be overwritten by DPV0
cyclic service. We provide an option in “slot 1
、
index 0
、
length 1” to change the
priority of DPV1 write acyclic service . The Default value is 0. To achieve the
higher priority of DPV1 write acyclic service , the value has to be set to “1”.
Example 1:
If user setup 3 modules in GW-7553-B / GW-7553-M, system setting module
、
2
