User manual

105G Wireless Gateway User Manual
Elpro_man_105g_1.18.doc Page 76
Discrete I/O
The value of a digital I/O point is stored in the 105G database as a hexadecimal '0000' (“off”) or hex
'FFFF' (“on”). However the 105G will generate either a ‘0’ (“off”) or ‘1’ (“on”) to a binary file
when initiating a “Typed Logical Write” command or responding to a “Typed Logical Read”
command. Similarly, the 105G will accept ‘0’ or ‘1’ from responding device to a “Typed Logical
Read” command or from an initiating device generating a “Typed Logical Write” command and
store ‘0000’ or ‘FFFF’ in the database location. The file type for a binary file (bit file) is 0x85.
In the PLC (that is, the DF1 host device), discrete values (“bits”) are stored in 16 bit registers - each
register stores 16 bit values (or 16 discrete values). You can only transfer these values in groups of
16. That is a read or write command will transfer a minimum of 16 bits to/from the 105G. If more
than 16 are transferred, then they will be transferred in multiples of 16. You cannot transfer an
individual bit - you must transfer the 16 bits in that PLC register, which will be transferred to/from
16 consecutive I/O registers in the 105G.
Note: The PLC reads or writes digital bits starting at the LSB of each register. In the 105G, only
one bit is written to each I/O register, and this is the MSB (Most Significant Bit).
Analog I/O
Analog I/O from the remote 105U modules are 16 bit register value. A value of 8192 (hex 2000)
represents 0mA. A value of 49152 (hex C000) represents 20mA. Each mA has value of 2048 (hex
0800) - a change of 4096 (hex 1000) is equivalent to a change of 2mA. A 4-20mA signal will vary
between 16384 (hex 4000) and 49152 (hex C000). A 0-20mA signal will vary between 8192 (hex
2000) and 49152 (hex C000).