560
N2 Override release time
(N2 OVER.REL.TIME)
Value:
1 - 65534 (OFF) sec.
OFF
Function:
In this parameter, the maximum time is set which is
expected to pass between the receipt of two N2 tele-
grams in a row. If this time is exceeded, the serial
communication is assumed to have stopped and all
points in the N2 point-map which are overridden will
be released in the order below:
1.
Release Analog Outputs from point address
(NPA) 0 to 255.
2.
Release Binary Outputs from point address
(NPA) 0 to 255.
3.
Release Internal Floating Points from point
address (NPA) 0 to 255.
4.
Release Internal Integer Points from point
address (NPA) 0 to 255.
5.
Release Internal Byte points from point ad-
dress (NPA) 0 to 255.
Description of choice:
Set the required time.
561
Protocol
(PROTOCOL)
Value:
FC protocol (FC PROTOKOL)
[0]
Metasys N2 (METASYS N2)
[1]
Modbus RTU
[2]
Function:
There is a choice of three different protocols.
Description of choice:
Select the required control word protocol.
For further information about using the Metasys N2
Protocol see MG91CX and Modbus RTU see
MG10SX.
570
Modbus parity and message framing
(M.BUS PAR./FRAME)
Value:
(EVEN/1 STOPBIT)
[0]
(ODD/1 STOPBIT)
[1]
(NO PARITY/1 STOPBIT)
[2]
(NO PARITY/2 STOPBIT)
[3]
Function:
This parameter sets up the drive’s Modbus RTU inter-
face to communicate properly with the master control-
ler. The parity (EVEN, ODD, or NO PARITY) must be
set to match the setting of the master controller.
Description of choice:
Select the parity that matches the setting for the Mod-
bus master controller. Even or odd parity is sometimes
used to allow a transmitted word to be checked for er-
rors. Because Modbus RTU uses the more efficient
CRC (Cyclic Redundancy Check) method of checking
for errors, parity checking is seldom used in Modbus
RTU networks.
571
Modbus communications timeout
(M.BUS COM.TIME.)
Value:
10 ms - 2000 ms
100 ms
Function:
This parameter determines the maximum amount of
time that the drive’s Modbus RTU will wait between
characters that are sent by the master controller.
When this amount of time expires, the drive’s Modbus
RTU interface will assume that it has received the en-
tire message.
Description of choice:
Generally, the value of 100 ms is sufficient for Modbus
RTU networks, although some Modbus RTU networks
may operate on a timeout value as short as 35 ms.
If this value is set too short, the drive’s Modbus RTU
interface may miss a part of the message. Since the
CRC check will not be valid, the drive will ignore the
message. The resulting retransmissions of messages
will slow communications on the network.
If this value is set too long, the drive will wait longer
than necessary to determine that the message is com-
pleted. This will delay the drive’s response to the mes-
sage and possibly cause the master controller to time
out. The resulting retransmissions of messages will
slow communications on the network.
= factory setting, () = display text, [] = value for use in communication via serial communication port
128
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