Delta RMC101 User Manual
Page 510
RMC100 and RMCWin User Manual
5-260
for the length, address, and checksum.
To write commands for 8 axes or 48 words:
To write 12 steps to the step table where each step is 8 words:
If more than 12 steps need to be transferred then more RS blocks are required to transfer the
remaining steps.
Data Consistency
When writing to the RMC it is often important that all the data is written at once so the RMC gets
the data in one scan. If the RMC uses partially updated data from the command area or the step
table, unintended results may occur. It is also important that the status area be from the same
RMC scan so that positions can be compared. The RMC guarantees data consistency over the
following areas:
1. Data from Status reads from RMC's registers D0 to D79 will be from the same scan.
2. Data written to the RMC's command registers from D80 to D127 will be processed in the same
scan.
3. Data read or written to the parameter area will be consistent if the transfer is 64 words or less.
This means that initializing all 8 axes with 128 words of data will take two RMC scans. This
should not be noticeable.
4. Data read or written to the step table is copied from the RMC's serial board to the step table in
100 word blocks. It is important that the RMC not execute a step that is partially updated.
Therefore the PLC should either:
a. Update the step table in blocks smaller than 100 words and in multiples of eight (8).
Transfer sizes like 64, 80 or 96 work well.
b. Stop the RMC from executing steps while downloading the step table.
c. Use the CommTrig (C) link type so the RMC waits until the last step is updated.
Errors
When the RMC returns a length of zero, the value in the address field is an error number. The
Error codes are as follows:
Value
Description
-1
Time Out:
More than 100 milliseconds has gone by with out
receiving a character.
-2
Overrun Error:
The RMC was not able to read the character in
the serial port before the next character over wrote it.