EPC120 EPC [Espros Photonics corp], EPC120 Datasheet - Page 20

• Manufacturer Part Number: EPC120
• Description: Fully integrated Light-Barrier Chips with 2-Wire Bus Interface
• Manufacturer: EPC [Espros Photonics corp]

Command NOP
Command TEST
Command RESET
Command ADRA
© 2011 ESPROS Photonics Corporation
Characteristics subject to change without notice
The command NOP can be used to fetch the last received data without sending a new command. With this command it is possible to monitor
the 2-wire interface by a second interface device in a redundant system.
The command TEST issues an internal test pulse or a DC current at the PD input pin on a specific receiver. It simulates basically a received
light pulse or DC sunlight influence to check the proper functionality of the receiver(s) without using an emitter. This mode is initialized by the
command TEST and is left after a complete SCAN sequence.
The applied current is the sum of different current sources: In column “Pulse Amplitude” of Table 9 a “1” means, that the corresponding
current is added. Example: 110000 generates a pulse of 75nA without DC.
The command RESET resets the device and initiates a startup. All devices can be reset simultaneously by using address 0.
ADRA is used during the configuration of a light curtain system to allocate a logical address to the physical position of the the emitter or
receiver element.
The command ADRA stores the device address to the volatile memory only (RAM). If the device address has to be stored permanently, the
command PROG has to be used to copy the previous stored device address from the RAM register into the ROM register. ADRA can only be
used if there was no previous PROG command to the address register.
The address 0 is reserved to address all devices together or none and must not be used as an individual address.
The command ADRA generates no result.
For details refer to Chapter Address Programming.
Data Bits
D
C
D
D
E
Code
11
0
5
0
0
111
… D
… C
… D
… D
D
D
… E
N
4
5
10
2
3
20
3
Table 8: Result of a SCAN command
Extension
Function
Indicates, if new data is available
Timestamp
Status of receiver threshold “normal”
Status of receiver threshold “high” (light reserve)
empty, not used
Device address
Error codes, refer to Chapter Error Codes
R
D
D
N
0
1
0
1
0
1
10000
0
4
4
… R
Values
no new data available
new data available
Values
Receiver threshold set by SENSN not reached
Receiver threshold set by SENSN exceeded
Values
Receiver threshold set by SENSH not reached
Receiver threshold set by SENSH exceeded
4
Table 9: Self Test
1xxxxx
x1xxxx
xx1xxx
xxx1xx
xxxx1x
xxxxx1
20
Amplitude
D
0
… D
25nA
50nA
100nA
100μA
500μA DC
2mA DC
4
Current Shape
Pulse
Pulse
Pulse
Pulse
DC
DC
Datasheet epc12x - V2.1
www.espros.ch
epc120