iC-MQ PROGRAMMABLE 9-BIT
Sin/Cos INTERPOLATION IC WITH RS422 DRIVER
Rev D4, Page 31/39
Error Protocol
Line Count Error
Out of the errors enabled by EMASKE both the first The line count error feature is particularly interest-
(under ERR1) and last error (under ERR2) which oc- ing for encoder systems. The disc is checked anew
cur after the iC-MQ is turned on are stored in the EEP- with each zero pulse, with the number of sine cycles
ROM.
counted until the next zero pulse occurs. If the direc-
tion of rotation is changed, the check is aborted.
The EEPROM also has a memory area in which all oc-
curring errors can be stored (ERR3). Only the fact that The line count is then stored under LINECNT minus 1,
an error has occurred can be recorded, with no infor- i.e. for a code disc with 256 lines LINECNT records
mation as to the time and count of appearance of that a value of 255. If the counted line number does not
error given. Error recording can be used to statistically match the number already stored in LINECNT, a line
evaluate the causes of system failure, for example.
count error is set. In mode System Test signal TP1
indicates when the line count check is first ended.
EMASKE
Adr 0x18, bit 5:0; Adr 0x17, bit 7:4
Error event
Bit
9
Temperature Monitoring
If the temperature warning threshold is exceeded an
excessive temperature message is generated which is
processed in the temperature monitor block (Tw corre-
sponds to T2).
Line count error (wrong count of sine periods
between two zero pulses)
8
7
6
5
4
—
Loss of tracking (excessive input frequency)
—
Excessive temperature warning
Exceeding the temperature warning threshold can be
signaled at pin ERR or used to shut down the line
drivers (via mask EMASKO). The temperature warn-
ing is deleted when the temperature drops below Tw
System error: I/O pin ERR reads low by an external
error signal (only permitted with EPH = 0)
3
2
1
0
Control error 2: range at max. limit
Control error 1: range at min. limit
-Thys
.
Signal error 2: clipping due to excessive input level
Signal error 1: loss of signal (poor input level or s/c
phase out of range)
If the temperature shutdown threshold Toff = Tw + ∆ T
is exceeded the line drivers are shut down independent
of EMASKO.
Code
Function
1
0
Enable: event will be latched
Disable: event will not be latched
Table 59: Error Event Mask for EEPROM Savings
ERR1
Adr 0x31, bit 1:0; Adr 0x30, bit 7:0
Adr 0x32, bit 3:0; Adr 0x31, bit 7:2
Adr 0x33, bit 5:0; Adr 0x32, bit 7:4
Error Event
ERR2
ERR3
Bit
6:0
Assignation according to EMASKE
Code
Function
0
1
No event
Registered error event
Table 60: Error Protocol
ICHAUS [ IC-HAUS GMBH ]
