IC-MQF_15 Datasheet, PDF (30/38 Pages) IC-Haus GmbH – Sin/Cos INTERPOLATION IC WITH RS422 DRIVER

iC-MQF PROGRAMMABLE 12-BIT ^preliminary
Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
ERROR MONITORING AND ALARM OUTPUT
Rev C1, Page 30/38
iC-MQF monitors the input signals, the internal inter-
polator and the sensor supply controller via which the
input signal levels are stabilized. If the sensor sup-
ply tracking unit reaches its control limits this can be
interpreted as an end-of-life message, for example.
Three separate error masks stipulate whether error
events are signaled as an alarm via I/O pin ERR (mask
EMASKA), whether they cause the RS422 line drivers
to shutdown or not (mask EMASKO) or whether they
are stored in the EEPROM (mask EMASKE).
Alarm Output: I/O-pin ERR
Pin ERR is operated by a current-limited open-drain
output driver and has an internal pull-up which can be
disabled. The ERR pin also acts as an input for external
system error messaging and for switching iC-MQF to
test mode for which a voltage of larger than VTMon
must be applied (see page 33). Interpretation of an
external system error message and the phase of the
message output is configured by EPH, the minimum
indication time by EMTD.
EMASKA
Bit
9
8
7
6*
5
4
3
2
1
0
Code
1
0
Notes
Addr 0x18, bit 1:0; Addr 0x17, bit 7:0
Error event
Line count error (wrong count of sine periods
between two zero pulses)
Temporal tracking error (out-of-sync: position output
differs from actual angle, e.g. after cycling power)
Loss of tracking (excessive input frequency)
Configuration error
(SDA or SCL pin error, no acknowledge signal from
EEPROM or invalid check sum)
Excessive temperature warning
Ungated index enable signal Z_In
(comparated X1/X2 inputs for CFGABZ and
CFGZPOS adjustment, at EMTD = 0x0)
Control error 2: range at max. limit
Control error 1: range at min. limit
Signal error 2: clipping
Signal error 1: loss of signal (poor differential
amplitude**, wrong s/c phase)
Function
Enable: event changes state of pin ERR
(if EMASKO does not disable the output function).
Disable: event does not affect pin ERR.
*) Pin ERR can not pull low on configuration error,
use high-active error logic instead (EPH = 1);
**) Also due to excessive input signals or internal
signal clipping.
EPH
Code
0*
1
Notes
Addr 0x1A, bit 4
State on error
State w/o error
active low
high impedance,
with input function for a
low-active system error;
high impedance
active low
*) Pin ERR is disabled during driver shutdown and
cannot indicate errors in this case.
Table 50: I/O Logic, Alarm Output ERR
EMTD
Code
0x0
0x1
0x2
0x3
Addr 0x18, bit 6:4
Indication Time
0 ms
12.5 ms
25 ms
37.5 ms
Code
0x4
0x5
0x6
0x7
Indication Time
50 ms
62.5 ms
75 ms
87.5 ms
Table 51: Min. Indication Time, Alarm Output ERR
Table 53: Error Mask Alarm Output ERR
Line Count Error
Line count monitoring is particularly interesting for en-
coder systems. iC-MQF counts the number of sine cy-
cles between two adjacent zero pulses and compares it
to the reference value LINECNT. In case of a deviation
the line count error is set. The check is paused if the
direction of rotation changes, and is restarted on the
next zero pulse. During mode System Test signal TP1
indicates when a first line count check has finished.
LINECNT
Code
0x0000
...
0x3FFF
Example
Addr 0x24, bit 5:0; Addr 0x23, bit 7:0
Function Value
Line Count (CPR)
0
1
...
Code + 1
16383
16384
Code disc of 256 CPR → LINECNT = 255
Table 54: Line Count Reference
EPU
Code
0
1
Addr 0x1A, bit 5
Function
No internal pull-up
Internal 300 µA pull-up current source active
Table 52: Pull-Up Enable, Alarm Output ERR
Excessive Temperature Warning
Exceeding the temperature warning threshold T_w (cor-
responds to T₂, refer to Temperature Sensor, page
17) can be signaled at pin ERR or used to shut down
the line drivers (via mask EMASKO). The temperature