User`s manual

197
CHAPTER 6 CHANGING THE DATA COMMUNICATIONS MONITORING TIMES
6
6.1 No-reception Monitoring Time (timer 0) Setting
(2) Changing the no-reception monitoring time (timer 0)
(a) Changing the no-reception monitoring time (timer 0)
The no-reception monitoring time (timer 0) is designated by the number of transmitted characters (byte count)
corresponding to the data communication rate set in the interface, and then it is registered on the GX
Configurator-SC's "Transmission control and others system setting" screen.
Adjust or set the value based on the specifications of the external device.
(b) No-reception monitoring time format specification in non procedure protocol
(Format 0/Format 1)
The no-reception monitoring time format in non procedure protocol is specified to use the no-reception
monitoring time (timer 0) by the non procedure protocol and is registered on the "Non procedure system
setting" screen.
Remark
• When changing the no-reception monitoring time (timer 0)
Find the result using the following expression and set the number of bytes or greater for the no-reception monitoring time
(timer 0).
Td: Maximum delay time for external device output processing (ms)
Vbps: Transmission rate (bps)
Calculation of no-reception monitoring time (timer 0)
• Transmission rate (Vbps): 9600bps
• Maximum delay time for external device output processing (Td): 50ms
In this case, actual monitoring time is as follows:
41 bytes  12
*1
 9600  1000 = 51.25ms
*1 Number of transmit bits per byte (Fixed)
• When exchanging data with the external device through the Q series C24 RS-422/485 interface and changing the
no-reception monitoring time (timer 0)
Find the result using the following expression and set the number of bytes or greater for the no-reception monitoring time
(timer 0).
Td: Maximum delay time for external device output processing (ms)
T1: External device side H/W gate OFF time (ms)
Vbps: Transmission rate (bps)
No-reception monitoring time (timer 0) = 1 +
Td × Vbps
12000
(Round up fractions below decimal point.)
No-reception monitoring time (timer 0) = 1 +
50 × 9600
12000
= 41 bytes
No-reception monitoring time (timer 0) = 1 +
(Td + T1) × Vbps
12000
(Round up fractions below decimal point.)