JVL MAC050 User Manual page 284

5.10
- When reading one or more register values from the basic motor, the remaining
operation of the module waits for the operation(s) to complete before continuing
operation. For the fieldbus modules, this means that the response time for a read
operation can be quite long, since in addition to the requested read operation, other
read and write operations can be queued up and must complete before the
requested read operation can be completed and the value can be returned over to
fieldbus. For the PLC-like modules, the long transmission time means that a program
line that manipulates a motor register in a way that requires reading can take 20 or
more milliseconds to execute.
- Some fieldbusses, like CANopen® expect that the motor is able to transmit a value
when it has changed more than a certain amount since the last time it was
transmitted. The current fieldbus modules do not have this capability since it would
load the serial link to the motor too much to continuously poll the value of motor
registers.
Module register addressing and module commands
Some of the modules have registers to control their behaviour. These register are ad-
dressed in another way than the registers in the basic motor. Examples include registers
that control digital inputs and outputs local to the module.
Additionally, the modules containing a nano-PLC have 256 bytes of memory local to the
module, that can be used to create variables that can be used during program execution,
typically for calculations. These local memory variables are much faster to use than the
registers in the basic motor since they are not transmitted over the relatively slow serial
line.
These module register are available over the MacTalk protocol and over the fieldbusses.
On the MacTalk protocol, the module registers are addressed differently for each mod-
ule type.
The general idea is that each module type has its own range of commands that is different
from the range used by the basic motor.
The three special commands Reset Motor, Clear Errors and Save in Flash:
Save in Flash:
Pressing this button in MacTalk will send a special command over the serial line (RS-232
or RS-485) that will cause the motor and module (if present) to save the setup registers
to flash memory. Flash memory is permanent storage that will keep its value even though
the power supply has been turned off.
At the next power up, the motor and module will load the saved values from flash. Note
that the motor, but not the module, will automatically perform a reset as soon as it has
finished the Save in Flash operation.
The operations performed by MacTalk are:
1: Set the motor into Safe Mode by sending a telegram of <54><54><54><FF>
<00><AA><AA> and wait for an answer with data <11><11><11>. If the
motor uses an address instead of using the broadcast address 255 (FF), substitute the
<FF><00> with <address><inverted address>. See the MacTalk protocol
description for more information.
2: Continue sending the telegram <56><56><56><FF><00><AA><AA> and
wait for the <11><11><11> sequence. As soon as any communications error
occurs, like a wrong answer or a missing answer/timeout, it means the motor has
started its reset sequence. Again, you can substitute a specific motor address for the
broadcast address <FF><00>.
280 JVL Industri Elektronik A/S - User Manual - Integrated Servo Motors MAC050 - 800
Serial communication