Mercury 2+ Operator Terminal User Manual
Page 77 of 82
2019r0
Registers 172...175 : 8 character string (no auto increment)
A quad set of Modbus registers will put 8 characters on the screen
at the current cursor position when the last of the 4 register quads
is written. The cursor position will not be moved. In each Modbus
register, the high order (D8D15) will represent the left hand
character ASCII value and the low order (D0D7) will represent
the right hand character of the pair. The next Modbus register will
represent the next pair of character positions.
Registers 176...195 : 40 character string (no auto increment)
This is similar to registers 172...175, but, by reserving 20 registers,
allows a complete line of 40 characters to be written in one go.
Register 196 : 2 character string (with auto increment)
A single Modbus register will be used which, when written to, will
put two characters on the screen at the current cursor position, and
then move the cursor position along two character positions. In the
Modbus register, the high order (D8D15) will represent the left
hand character ASCII value and the low order (D0D7) will
represent the right hand character of the pair.
Registers For Receiving Data from the Mercury 2+
Register 1 : Data Pending
A single resister can be read to determine if there is any valid data
in the Card Reader or Text input registers. This single register
contains 3 separate numbers, each corresponding to the number of
relevant readings that are currently buffered in the Mercury 2+,
waiting to be read.
D0D3
Number of buffered text messages
D4D7
Number of buffered card readings
D8D15
Reserved
Register 2 : Function Keys
D0D7
1 means Function Keys F1 to F8 have been pressed
Registers 3...18 : Proximity Card Reading
A set of 16 Modbus registers are used to hold the Proximity card
reading.
Up to 5 Proximity card readings may be buffered, waiting to be
read. If further Proximity card readings are made without the
buffer being read, the subsequent data is lost.
For each Modbus register, the high order (D8D15) will represent
the left hand character ASCII value and the low order (D0D7) will
represent the right hand character of the pair.
If the Proximity card reading is less than 32 characters long, then
the Modbus register "half" following the last valid character will
have the value 00
H
, as will all the other Modbus registers in the
rest of the register set.
Note: only when register 18 is read will the next buffered reading
be made available.
