Page Unit

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Displays information about each I/O Device in the Citect system. This information is displayed if the Citect computer is configured as an I/O Server or simply as a client. If the computer is a client, then every I/O Device for every I/O Server is displayed. If the computer is an I/O Server, then only the I/O Devices for that I/O Server are displayed. You can display I/O Devices from other I/O Servers by using the Verbose mode (press V to enable Verbose mode). If the computer is a client, then not every one of the I/O Device Information is updated (because only the I/O Server has this information).

Syntax

Page Unit

If the Citect computer is a client, the status and error codes are only local to the computer and do not reflect the true status of the I/O Device on the I/O Server. Be aware that every configured I/O Device is displayed in this window, not just the I/O Devices for the particular I/O Server. (Any remote I/O Devices do not reflect the true status of the I/O Device).

Use the Page Up and Page Down keys to scan the I/O Device list.

I/O Device Information

I/O Device	The name of the I/O Device defined in the project (with the I/O Devices form).
I/O Server	The name of the I/O Server that is servicing this I/O Device.
Comment	A description of the I/O Device defined in the project (with the I/O Devices form).
I/O Device No	The I/O Device number defined in the project (with the I/O Devices form).
PLC Number	The physical I/O Device address defined in the project (with the I/O Devices form).
Port Name	The communication port to which the I/O Device is connected.
Protocol	The protocol used for communication with the I/O Device.
Server Status and Client Status	The status of the I/O Device. The Server Status is only valid if the computer is an I/O Server and it is servicing this I/O Device. The Client Status field is valid for Clients only, and indicates the status of the I/O Device that is attached to the I/O Server. The I/O Device status can be one of the following: RUNNING - Indicates that the communication link with the I/O Device is good. STANDBY - Indicates that the communication link with the I/O Device is good, but communication with that I/O Device is currently being performed by another port. This port is in standby mode. STARTING - Indicates that the server is currently establishing a communication link (with the I/O Device). STOPPING - Indicates that the server is currently relinquishing control of the communication link (with the I/O Device). OFFLINE - Indicates that the server cannot establish a communication channel with the I/O Device. If a standby port or server is available, Citect tries to communicate to the I/O Device using that port. REMOTE - Indicates that the status of the I/O Device is OK, but it is not currently connected.
Primary	Indicates if the I/O Device is in primary mode; Yes = Primary, No = Standby. If the I/O Device is in primary mode, the server starts a communication channel with the I/O Device as soon as the server is activated. If an I/O Device is in standby mode, the I/O Device remains inactive when the server starts (until a primary I/O Device becomes inoperative).
Client Using	The name of the I/O Server that this client is using. This allows you to identify the primary and standby I/O Servers.
Generic Error	The last generic error code returned by the driver. Because most protocol drivers have their own special errors, they cannot be recognized by the I/O Server. The drivers convert their special errors into generic errors that can be identified by the server.
Error Handle	The error handle that is assigned by the I/O Server to each error. This handle is not used by Citect (at this time).
Driver Error	The driver-specific error code. Each driver has its own special error codes. Refer to the driver specific errors (for the particular protocol) for an explanation of each of the error codes.
Error Message	The alert message associated with the generic error code.
Error Count	The total number of errors from the I/O Device.
Restarts	The number of times the server has tried to establish a connection with the I/O Device. This number is normally 1, because the server establishes a connection at startup. If this field displays a number greater than 1, there is a problem with the communication channel.
Response Times	The time taken by the driver to process read and write requests (i.e. the time taken to process a single read or write operation to the I/O Device). This time depends only on the physical response time of the I/O Device, because no queue waiting time is included. This field reflects any tuning of the communication channel (for example doubling the baud rateThe number of times per second a signal changes in a communication channel. While the baud rate directly affects the speed of data transmission, the term is often erroneously used to describe the data transfer rate. The correct measure for the data rate is bits per second (bps). will half the response time). The average, minimum, and maximum times are displayed. Note: One I/O Device with a slow response can slow down your entire system. For example, if you have an I/O Device with a response of 2000 ms, any pages in your system that use data from that device, will have a minimum update time of 2000 ms.
Cached	This field indicates if the I/O Device data is cached.
Cache Timeout	If the I/O Device is cached, this field displays the cache timeout value. Data is held in the cache for this timeout period before being discarded and re-read from the I/O Device. Only read data is cached.
Blocking Constant	The current blocking constant value for this I/O Device, as specified in the protocol.
Dial-up Connection	The status and history of the dial-up connection. SUCCESS - The number of successful dial-up attempts. FAIL - The number of unsuccessful dial-up attempts. TOTAL - The total number of dial-up attempts. NEXT - The time of the next scheduled dial-up attempt.