Start And Turning Off Of The System; Real-Time Circuit; I/O Circuits; Printing Control Circuits - ELCOM EURO-2500 Service Manual

© Elcom s. r. o.
To preserve the data in the RAM memory while the ECR is off, the memory power supply is backed up from the accumula-
tor.
2.2.3 Start and turning off of the system 2.2.3 Start and turning off of the system
The mostly importat system states are its start and its turning off. During the system start it is necessary to properly initialise
the microcontroller and all the logical circuits and during the turning off it is necessary to save all the vital data and to secure
the microcontroller and logical circuits into a safe state.
The E-2500N microcontroller connection configuration has been engineered so that even when the ECR is turned off, the
E-2500N is powered from the back-up NiCd accumulator, i. e. its power input equals VRAM (current consumption is approx.
500 nA). In order to correctly turn the system on and off it is required to set the RESET and STBY (stand-by mode activation)
signal activation properly. These signals are controlled by their respective controllers (reset and stand-by controllers).
Reset controller is a circuit that secures:
• reliable initialisation of the E-2500N microcontroller during the ECR activation via the active level of RESET signal
• activation of RESET signal when the VCC power supply drops to the circuit's treshold level
Active level of RESET signal is "log.0". Active level duration is min. 150 ms. Treshold level is the voltage level that causes the
RESET signal generation. This treshold value is critical for the proper function of the logical circuits. Treshold value for the
V6309 circuit used in the ECR is 4.5 V. The V6309 causes the CPU reset when the voltage drops below 4.5 V.
Stand-by controller is a circuit that secures:
• reliable leaving of the E-2500N microcontroller stand-by mode during the turning on of the ECR
• activation of STBY signal when the VCC power supply drops to the circuit's treshold level
Active level of the STBY signal is "log.0". Treshold value for the V6309/F circuit used in the ECR is 4.5 V. The V6309/F causes the
CPU to enter the stand-by mode when the voltage drops below 4.5 V. If the voltage drop is lansting longer, the CPU remains
in the stand-by mode.
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Fig. 2.7: Reset controller

2.2.4 Real-time circuit

2.2.4 Real-time circuit
ECR Euro-2500TX requires the real-time function. This function is provided by
the V3021 circuit. Communication between them is performed using the D0
data line and the RD and HWR control signals. The circuit itself is activated by
the CSCRT signal. In order for the circuit to function properly while the ECR is
off, its power is backed up from the NiCd accumulator. While the ECR is off, the
consumed current from the accumulator is max. 500 nA.

2.3 I/O circuits

2.3 I/O circuits

2.3.1 Printing control circuits

2.3.1 Printing control circuits
The Euro-2500TX ECR uses the thermal printer SEIKO LTP 2W42. In order for the
printer to function properly it is required to control:
• signals for the actual printing
• printer step motors
• journal winding motor
• paper tape cutter (if supplied)
and it is necessary to check:
Euro 2500
TX
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Fig. 2.8: Stand-by controller
Fig. 2.9: Real-time circuit
Service manual
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