Fig. 2.29 Communication Circuits And The External Pc Keyboard Interface - ELCOM Euro-500 Handy Series Service Manual

Euro-500TX Handy
The communication with the PC is possible via the RS-232 interface. The correct setting of the ECR num-
ber is a vital parameter for this communication (see Programming manual – Flag programming). The ECR
is able to communicate with the PC in any of its modes if no other operations take place (e. g. an unfinished
sale).
In order for the ECR to communicate with PC or scanner properly it is necessary to set the same parame-
ters for both devices. The ECR allows the programming of these parameters in its programming mode (see
Programming manual – Flag programming).
Adjustable transfer parameters for both devices (PC and scanner) are:
• PC communication speed
• scanner communication speed programmable from 1,200 to 19,200 Bd
• data bits
• parity
• stop bits
• scanner terminal character
Communication with electronic scales is defined by these parameters:
• communication speed
• data bits
• parity
• stop bits
• communication protocol
The ECR is capable of communicating with any PC keyboard of PS/2 type.
PCTxD
SCLTxD
PCRxD
SCLRxD
SCRRxD
C102
1n
Fig. 2.29 Communication circuits (PC, scanner, scales) and the external PC keyboard interface
Note: Further information on connection of external devices (PC, scanner, scales, PC keyboard) are descri-
bed in chapter 4.
Service manual
programmable, 9,600 or 38,400 Bd
8
none
1
programmable: CR, LF, or CR + LF
9,600 Bd
8
none
1
Euroscales, MORCAN or MACCA scales
B40
EBM2012
14
B41
13
EBM2012
C17
100n
C100
1n
C101
1n
C18
100n
B42 R101
EBM2012
R100
D12
4k7
LL4148
B43
R106
47k
EBM2012
B44
R105
EBM2012 4k7
D11
LL4148
C104
1n
EKB-DATA
EKB-CLKA
C71
1n
U9
TxD0
11
T1OUT T1IN
TxD1
7 10
T2OUT T2IN
12
R1IN R1OUT
C20
8 9
R2IN R2OUT
100n
2 1
V+ C1+
3
C1-
4
C2+
6 5
V- C2-
HIN202
C19
100n
R103
100k
47k
D13
R102
LL4148
22k
R108
100k
D14
R107
LL4148
22k
VCC
R110 R111
47k 47k
B45
EBM2012
EKB-DAT
EKB-CLK
B46
EBM2012
C72
1n
© Elcom, s. r. o.
D19
VCC1
FMKA140
C38
100n
R104
10k
RxD0 VCC
T11
BC817
R109
10k
RxD1 VCC
T12
BC817
23