Delta RMC151 - Manual (Page 536)

RMC70/150 and RMCTools User Manual
Registers 0-7 of the Response Block return the values from 8 registers, which must be
determined when setting up the communications. However, it is possible to set up one of
the registers 1-7 in the Response Block to return the value of a read from any single
register in the RMC70.
When a read is requested from any single register in the RMC70, the response from this
single-register read will be placed in the Axis 0 Read Response register. In order to see
the response from the PROFIBUS, you must map the Axis 0 Read Register into one of the
Indirect Data Map registers.
Notice that the copy from the requested register into the Axis 0 Read Response register
only occurs once, and therefore you will not see the value continuously updating like the
other Response Block registers.
To read any single register from the RMC70, use the following steps:
• Wait until the Response Block register 0 Read/Write Request bit is equal to the
Command Block register 6 Read/Write Acknowledge bit. If they are not equal, the
RMC70 is currently processing a read or write request.
• Clear the Command Block register 6 Read/Write bit.
• Set the Command Block Register 6 Read/Write Address File and Read/Write Address
Element. For example, for address %MD8.12, the file is 8, and the element is 12. For
a description of all RMC70 registers and their addresses, see the RMC70 Register Map
topic.
• Toggle the Read/Write Request bit.
• Wait until the Read/Write Request bit is equal to the Read/Write Acknowledge
bit. When they are equal, the RMC70 will have updated the Axis 0 Read Response
register with the requested data, and the corresponding Response Block register.
To further clarify the ordering, keep these basic rules in mind:
• Do change the read address and Read/Write bit before toggling the Read/Write
Request bit.
• Do not change the Read/Write Request bit after a read request until you have
processed the data in the Read Response register.
• Do not change the read address or Read/Write bit when the Read/Write Request
bit does not match the Read/Write Acknowledge bit.
Read Any Contiguous RMC70 Registers
To read any contiguous RMC70 registers, use the Command Block register 8 and the
Response Block registers 8-15.
To read any contiguous RMC70 registers, use the following steps:
• Wait until the Command Block register 8 Read/Write Request bit is equal to the
Response Block register 8 Read/Write Acknowledge bit. If they are not equal, the
RMC is currently processing a read or write request.
• Clear the Command Block register 8 Read/Write bit.
• In the Command Block register 8, set the Read/Write Address File and Read/Write
Address Element to the first RMC70 address you wish to read. For example, for
address %MD8.12, the file is 8, and the element is 12. Set the Count to the number of
register to read, up to 7. For a description of all RMC70 registers and their addresses,
see the RMC70 Register Map topic.
• Toggle the Read/Write Request bit.
• Wait until the Read Request bit is equal to the Read/Write Acknowledge
bit. When they are equal, the RMC70 will have updated the Response Block registers
8-15 with the requested data.
516 Delta Computer Systems, Inc.