Toshiba XLTR-200 Manual De Usuario

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slave.  This gateway follows this generally-accepted industry paradigm, 
where a point’s configured Modbus master “register” value is decremented 
by 1 before it is placed “on the wire”.  Some vendors, however, will 
document their slave device’s “addressed as” values in their literature, 
which means that these register indices must have 1 added to them when 
entered into the gateway’s “Modbus master register” field. 
 
For example, the Toshiba VF-AS1 drive’s Modbus RTU slave protocol 
implementation & corresponding user’s manual references all internal ASD 
parameters using “addressed as” values.  This means that (in addition to 
the required conversion from Toshiba’s native hexadecimal radix to the 
Modbus protocol’s natural decimal radix) these parameter values must 
have 1 added to them when they are to be accessed via an ICC gateway 
executing the Modbus RTU master protocol. 
 
e.g VF-AS1 “command 1” parameter is documented to be FA00 in the 
Toshiba literature.  Converting this to decimal, we arrive at a value of 
64000.  To allow a point in the gateway’s database to correctly access the 
“command 1” parameter via Modbus RTU, therefore, that point’s Modbus 
master “register” attribute must be set to 64001 (which will result in an 
address value of 64000 (0xFA00) “on the wire”).