User manual
9 Functions and operations in the position control mode
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• Checksum (8 bit)
The 48 bits of current position and status information are divided into bytes, and all bytes are added up.
The checksum represents the last 8 bits in the result obtained by a total of six additions (addition of six bytes).
This information is used to check if the data has been read correctly.
Example: Data output from the driver when the current position corresponds to
12345 steps and an overload alarm is present
0000 0000 0000 0000 0011 0000 0011 1001 0000 0000 0011 0000 1001 1001
Current position Status Alarm Checksum
After the data has been read, all bytes constituting the current position (32 bits), status (8 bits) and alarm code
(8 bits) read into the programmable controller are added up.
0000 0000 + 0000 0000 + 0011 0000 + 0011 1001 + 0000 0000 + 0011 000
0
Result = 0000 0000 1001 1001
Last 8 bits (1 byte)
The checksum represents the last 8 bits, or “1101 0001” in the above example.
If the calculated result matches the checksum value read from the driver, the data have been read correctly.
I/O signals used
The signals used in the current position output mode are indicated. This information is sent by input pin 2 and
output pin 3.
Normally other signals are assigned to the P-CK input, P-OUTR output, P-OUT0 output and P-OUT1 output.
When the P-REQ input turns ON, these signals function as the P-CK input, P-OUTR output, P-OUT0 output
and P-OUT1 output.
Note, however, that when the P-REQ input is ON, the current position output function is given priority.
Accordingly, the CLR/ALM-RST input, READY/AL0 output, TLC/AL1 output and ZSG2/NEAR/AL2
output will not function.
Signal name Description
P-REQ input The programmable controller uses this signal to
request the transmission of data.
P-CK input (normal: CLR/ALM-RST input) This signal is used to request data (clock).
P-OUTR output (normal: READY output) This signal indicates that data is ready for
transmission.
P-OUT0 output (normal: TLC output)
P-OUT1 output (normal: ZSG2/NEAR output)
These signals indicate two bits of data. The P-OUT0
output represents the low-order bit, while the P-OUT1
output represents the high-order bit.
The P-REQ input is always enabled. When the P-REQ input is ON during operation, the current position,
status and alarm code are transmitted.