User manual - INDICATOR TRS-10a
TRS
system, all predefined error
codes are compatible to error codes which may occur in this system. Values
transmitted to register 02h in „”
decimal mode”
are limited. Higher byte can be
set to: 00h, 2Xh, 4Xh, 8Xh and Fxh, lower byte to 00h, 01h, 02h i 03h.
If user tray to write values other than mentioned above exception code 03h
occurs, and displayed value will not change.
In „
byte mode
” register 02h has different meaning. In this mode it directly
drives segments of decade 2 (higher byte) and segments of decade 3 (lower
byte - see Tab.5.1). Similarly as for register 01h, logical 1 on particular bit turn
on corresponding segment. In „
byte mode
” range of value stored to register
02h is 0000h ÷ FFFFh.
After power switch on, if display has been set to „
decimal mode
” then higher
byte of this register is cleared, and lower byte is set to previously set value
(decimal point position is saved to EEPROM while power switching off), display
shows "
- - - -
", as long as first correct MODBUS transaction will occur.
If before power off, module has been set to „
byte mode
”, then after power on
content of register 02h is set to value 4040h, what is equal to displays of "
-
"
on appropriate decades.
Register 03h
- Status register. Higher byte of this register is always 0. If display is in
„
decimal mode
” lower byte of reg. 03h is a copy of higher byte of register
02h. Similarly it can get only limited values (see Tab. 5.2), and other values
causes exception code 03h. Module reacts to all changes of lower byte of
reg. 03h as for changes of higer byte of reg. 02h. Changes of lower byte of
reg. 03h causes of automatical change of higher byte of reg. 02H - these two
bytes are interdependent.
If display is in „
byte mode
” , register 03h is cleared, and unavailable to write,
lower byte of reg 03h is not a copy of higher of reg. 02h. In this mode content
of register 03h is cleared after power switch on.
Register 04h
- Refresh period. After data writing to any of the registers, display shows in
continuous mode value/warning according to registers 01h and 02h content.
Continuous displaying is continued as long as refresh period elapse. After that
displayed text starts to flashes, signalising that, defined time elapsed since
last correct MODBUS transaction with display module. This signalisation
allows to control correctness of MASTER system operation. Time elapsed
from last correct MODBUS transaction is cleared after every data writing to
registers 01h - 05h and 20h of the display module – if particular register allows
writing in current mode (see descriptions of registers 03h and 05h). Refresh
period control can be switched off, writing value FFFFh (65535) to register
04h, or set any other value from range 100h - FFFEh (256 - 65534)
expressed in seconds - (from about 4 minutes to about 18 hours).
If user tray to write values other than mentioned above exception code 03h
occurs, content of register 04h will not be changed, and elapsed time will be
counted so on.
After power switch on, refresh time is temporarily off, until first correct write to
any of writeable registers. After that control of refresh time is continued witch
settings stored before power switch off (it can be permanently switched off)-
this set is saved in EEPROM.
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