EPC100 Datasheet, PDF (5/9 Pages) Espros Photonics corp – Light-Curtain Device with 2-Wire Bus Interface

epc100
Overview Functional Description
Light Curtain Receiver in a 2-Wire Configuration
I_TE
VDD
R_TE
VDD µC
µC
GND
VDD
epc100
VDD33 I
F
SI
SO
SCK
CS
GND
Rx Element 1
VDD
epc100
VDD33 _R
PD
1
VDD18
GND
Rx Element 2
VDD
epc100
VDD33 _R
PD
2
VDD18
GND
Figure 4: Typical light curtain receiver edge circuit
Rx Element n
VDD
epc100
VDD33 _R
PD
n
VDD18
GND
The epc100 device can be operated in two different modes:
a) Photo Current Receivers
It detects current pulses of the photo diode generated by light pulses and transmits the information using the 2-wire bus to a central con -
troller, i.e. a micro controller. The devices operating as this photo current receivers are designated in the schematic diagram above as R1 to
Rn.
b) 2-Wire Bus Interface of the Central Controller
It manages the 2-wire bus traffic between the micro controller and the individual photo current receivers. The device operating as the inter-
face unit is designated as IF.
From the point of view of the micro controller, the whole system looks like a single device with several addressable photo diodes. The micro
controller activates one photo diode and fetches the results after a predefined time. Each sensor device has two different operation modes: A
standby_Aa_Nn_ed_pa_cn₁₀o₀pe_ligra_ht_tin_cg_urm_tao_ind_re_e._cD_eu_ivr_ein_rg the
ode is shorted. During the operation mode,
standby mode the power consumption is reduced^La^STnd the DC
the micro controller addresses one device after the other and
current
fetches
gen¹⁸e^.0r⁵a^.2te⁰¹d¹
the^Par^ge^es¹ult.
in the photo di
The result con
-
-
T^Fhⁱi^ls^ed^:o^tlc_iau_gm^iheⁿn_tt^sis_pc^to_uhnf_li^ed_sen_eitiⁿal_hfa^on_ad^rsp^mro_bte^ac_ete^td_eiob_nyⁿla_rw^wean_chd_ein^et_ie^tvr^hn_ea^eti_don^ra_il^antrad^lre^ies^g. I_sht m_ptu_es^pt n_cuo_tt ^lb^ste_os^eho_tw^hhn^aeto^sa_rn_ey^bth_ceir_ed^ep_ia_vnrt_ey n^ro^ewr b^ce_ineco_dip^vie_oed_win^da_.nⁱyⁿform^awi^ptho^ru^et o^dur^ewr^fitⁱteⁿn^epe^drmis^rs^eion^c. ^{eive window or not. It also contains the time point when the}
The receiver channel detects current pulses which are generated by light pulses in the photo diodes. The detection circuitry has two trigger
levels, hereinafter called thresholds, which form a digital signal from the analog current change. The lower threshold is called OUTN (normal)
whereas the upper level is called OUTH (high). Both trigger thresholds can be configured individually per chip. Please refer to Figure 2 and to
the Reference Manual epc10x which contains the configuration information.
© 2011 ESPROS Photonics Corporation
5
Characteristics subject to change without notice
Datasheet epc100 - V2.1
www.espros.ch