IS220PAICH1A燃机通用电气,IS220PAICH1A使用过程
典型情况下，该字段显示PROFIBUS一次扫描所需的估计时间（µs）网络这是一个只读字段。最小以100微秒为增量的最小输入/输出扫描时间。如果输入/输出模块的扫描频率受到限制。要使用此参数，单击最小值复选框将其激活，然后在其旁边的字段中输入值。这个您在此处输入的值表示100微秒的增量。
IS220PAICH1A燃机通用电气对于例如，在上图中，该值为2 x 100=200微秒。扫描周期时间“参数”组这些参数允许您设置看门狗定时器。自动最大输入/输出扫描时间和看门狗定时器自动分配。最大以10毫秒为增量的最大输入/输出扫描时间。如果扫描时间超过此值值时，PROFIBUS主设备对所有从设备进行故障诊断、重新初始化并将其恢复重新上线。当更新最大输入/输出扫描时间时，看门狗计时器也会已更新。如果PROFIBUS从站未从其主站接收到任何通信，则为看门狗时间，从机产生故障，输出设置为0，从机为通过PROFIBUS主卡重新初始化。赋值会影响最大循环时间选项参数组中继器如果网络上有中继器，请选中此复选框。如果存在PROFIBUS FMS（现场总线消息规范），FMS设备选中此复选框网络上的设备。出错时保持脱机如果您希望PROFIBUS主机在令牌出现时保持脱机，请选中此复选框256个令牌周期内超过错误限制或响应错误限制。
Typical
This field displays the estimated time (µs) required for one scan of the PROFIBUS
network. This is a read-only field.
Minimum
The minimum I/O scan time in 100 microsecond increments. This may be required if the
I/O modules are restricted in how often they can be scanned. To use this parameter,
click the Minimum check-box to activate it, then enter the value in the field next to it. The
value you enter here represents the number of 100 microsecond increments. For
example, in the figure above, the value is 2 x 100 = 200 microseconds.
Scan Cycle Times
Parameter Group
These parameters allow you to set minimum and maximum scan cycle times for the
Watchdog timer.
Auto
The maximum I/O scan time and Watchdog timer are assigned automatically.
Maximum
The maximum I/O scan time in 10 millisecond increments. If the scan time exceeds this
value, the PROFIBUS Master faults all the slaves, reinitializes them, and brings them
back online. When the maximum I/O scan time is updated, the Watchdog timer is also
updated.
Watchdog
If a PROFIBUS Slave does not receive any communication from its master within the
Watchdog time, the Slave generates a fault, the outputs are set to 0, and the Slave is
reinitialized by the PROFIBUS Master card. Assigning a value affects the maximum
cycle time.
Options Parameter Group
Repeater
Select this check box if there are repeaters on the network.
FMS Devices
Select this check box if there are PROFIBUS FMS (FieldBus Message Specification)
devices on the network.
Stay Offline on Error
Select this check box if you want the PROFIBUS Master to stay offline when the Token
Error Limit or response Error Limit is exceeded within 256 token cycles.
