ES58 • EM58 MODBUS®
[00][04] = number of requested registers
[08] = number of bytes (2 bytes for each register)
[00][00] = value to be set in the register 1
[08][00] = value to be set in the register 2, 00 00 08 00 hex = 2048 dec
[00][80] = value to be set in the register 3
[00][00] = value to be set in the register 4, 00 80 00 00 hex = 8 388 608 dec
[B6][DA] = CRC
The full frame needed to send back a response following the request to write the
value 2048 next to the
Custom counts per revolution [0000-0001 hex]
parameter (registers 1 and 2) and the value 8388608 next to the
parameter (registers 3 and 4) from the Slave
having the node address 1 is as follows:
Response PDU
(in hexadecimal format)
[01][10][00][00][00][04][C1][CA]
where:
[01] = Slave address
[10] =
function code
[00][00] = starting address (
Custom counts per revolution [0000-0001 hex]
parameter, register 1)
[00][04] = number of written registers
[C1][CA] = CRC
WARNING
For safety reasons, when the encoder is on, a continuous data exchange
between the Master and the Slave has to be planned in order to be sure that the
communication is always active; this is intended to prevent danger situations
from arising in case of failures in the communication network.
For this purpose the Watchdog function is implemented and can be activated as
optional. Watchdog function is a safety timer that uses a time-out to detect
loop or deadlock conditions. For instance, should the serial communication be
cut off while a command is still active and running Watchdog safety system
immediately takes action and commands an alarm to be triggered. To enable the
Watchdog function, set to “=1” the
variable. If “=0” is set the Watchdog is disabled; if “=1” is set
the Watchdog is enabled. When the Watchdog function is enabled, if the device
does not receive a message from the Server within 1 second, the system forces
an alarm condition (the
alarm message is invoked to appear as soon
as the Modbus network communication is restored).
MAN ESx58x_EMx58x MB E 1.3
MODBUS® interface
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