User manual - INDICATOR TRS-10a
5.
PRINCIPLE OF OPERATION
is equipped with 4 digits, seven segment, high bright LED
display. After switching the power on there in symbol "
- - - -
" on the display, informs user that
module is ready to work.
Display has two operation modes:
–
basic mode called „
decimal mode
" in this manual – this mode allows direct displaying of
transmitted values as decimal digits, and displaying defined warnings.
–
second mode called „
byte mode
” in this manual allows to display user defined symbols
Seven holding registers is used to service device: 01h to 05h, and 20h, 21h :
Register 01h
- in
"
decimal mode
" it is register of displayed value. All data written to this
register is displayed on the local display as decimal value. Register accepts
values in U2 code of range -999 to 9999. If user try to store value out of this
range, an error occur – device answers with exception code 03 (improper data
value), and displayed value will not change.
After switching power on, if display has been set to „
decimal mode
” then
register 01h is cleared (to 0000h), and symbol "
- - - -
" is showed on the
display.
While normal operation storing of value 0000h in register 01h, cause
displaying of "
0.
", "
0.0
", "
0.00
" or "
0.000
" depends on lower byte of register
02h (in decimal mode it is decimal point position and status).
- in „
byte mode
” this register drives directly segments of the display. Higher
byte of register 01 drives decade 0 (most right) and lower byte drives
segments of decade 1 (see Figure 5.1). While particular bits are set to 1
corresponding segments light (see Tab.5.1). In this mode register accepts
values of full range 0000h ÷ FFFFh.
After switching power on, if display has been set to „
byte mode
” then register
01h is set to 4040h, and symbol "
- - - -
" is showed on the display.
decade
no. 3
decade
no. 2
decade
no. 1
decade
no. 0
Figure 5.1. Decade and segments layout
9
