Omron NX-EC0112, Руководство пользователя

Страница: 239 / 468

7 - 33
7 SSI Input Units
NX-series Position Interface Units User’s Manual (W524)
7-7 I/O Da
ta S
p
ec
ification
s
7
7-7
-2 Dat
a Det
ails
The bit configuration of the Encoder Present Position parameter is given in the following table.
n: Channel number
Frame Error This error occurs when
an SSI data input is not
at low level
*1
in the next
clock cycle after the
final bit of SSI data is
received.
• The SSI settings are incorrect.
• An SSI communications line
(clock output or data input) is dis-
connected. Or, the clock output
(C+ and C-) is connected with
reversed polarity.
• There is noise on an SSI commu-
nications line.
• There is an encoder or Unit mal-
function.
• Set the correct SSI settings for the
connected encoder.
• Check the wiring to the SSI encoder.
• Remove the sources of any noise
around the SSI communications
lines.
• Replace the encoder or Unit.
Parity Error This error occurs if the
results of a parity check
performed on received
data detects an error. • There is a problem with the parity
check settings.
• There is noise on an SSI commu-
nications line.
• There is an encoder or Unit mal-
function.
• Set the correct SSI settings for the
connected encoder.
• Remove the sources of any noise
around the SSI communications
lines.
• Replace the encoder or Unit.
Communications
Timeout This error occurs if the
SSI data input is not at
high level after the
monoflop time elapses
and the SSI data is
received. • The SSI settings are incorrect.
• The SSI communications line for
clock output was disconnected
during communications.
• There is noise on an SSI commu-
nications line.
• There is an encoder or Unit mal-
function.
• Set the correct SSI settings for the
connected encoder.
• Check the wiring to the SSI encoder.
• Remove the sources of any noise
around the SSI communications
lines.
• Replace the encoder or Unit.
Out of range for
position difference If error data detection is
enabled, this error
occurs when a change
that exceeds the posi-
tion variation limit is
detected in SSI data. • There is noise on an SSI commu-
nications line.
• There is an encoder or Unit mal-
function.
• Remove the sources of any noise
around the SSI communications
lines.
• Replace the encoder or Unit.
*1. The low level is the state when the SSI data frame ends in 0.
Encoder Present Position
Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 CVn (Chn Encoder Present Position LL)
+
1 CVn (Chn Encoder Present Position LH)
+ 2 CVn (Chn Encoder Present Position HL)
+
3 CVn (Chn Encoder Present Position HH)
Abbr. Data Description
CVn Chn Encoder Present Position This contains the present position of the encoder for channel n.
Error description Detection details Assumed cause Possible correction