chenhsong.github.io

iChen® System 4 MIS/MES Integration Guide

Copyright © Chen Hsong Holdings Ltd. All rights reserved.
Document Version: 4
Last Edited: 2018-01-23

A Machine is NOT an Island

When a machine is connected via a network to the iChen® System 4, it can integrate with the MIS (Manufacturing Information System) or MES (Manufacturing Execution System) of the factory. When integrated, the machine stops being a stand-alone island, but instead becomes part of a larger, coherent, networked scheme.

An MIS/MES communicates with the iChen® Server via the Open Protocol™.

The MIS/MES must JOIN to the iChen® Server with a password that has the required authority (see here for details).

The iChen® Server sends Open Protocol™ messages to the MIS/MES and the MIS/MES responds with appropriate reply messages:

MIS/MES Communications Chart

Integrated Security

Normally, the controller on a machine controls access via a number of password levels, with higher levels having wider access powers than lower levels. Typically, an password level of zero indicates no authority to do anything on the machine.

Manually updating and managing password levels on multiple machines is time-consuming, resource-intensive and error-prone. It is also a significant security risk - for example, it is usually infeasible to change all the passwords on each machine each time when a staff has resigned or been transferred, and to redistribute the new passwords to all remaining staff. As a result, machine access in a typical production environment is usually kept loose, difficult to track and trace.

The iChen® System 4 provides audit trail features that automatically logs each and every single change of setting made on each connected machine, as well as logging each and every alarm condition that ever occurred. Even though this provides tremendous value for tracing out problems after they happened, it does not help in tracking who was responsible for the changes, and certainly does not help in preventing unauthorized changes in the first place.

In order to provide centrally-controlled authentication and authorization, the iChen® System 4 can integrate with the MIS/MES for complete lock-down and control of access to all machines.

When a machine is connected to the iChen® System 4, the internal password levels stored in its controller are disabled in favor of centralized security. Therefore, no operator can gain access to a machine that is connected to the iChen® System 4 by entering an internal password.

The operator instead must enter a password that is unique to him/her only, and not shared by anybody else in the company. Essentially, the operator’s personal password identifies the person involved. Some companies integrate staff card readers to machine controllers and dispense with the need to manually enter passwords altogether.

Upon receiving the personal password of the operator, the iChen® System 4 sends to the MIS/MES a LoginOperatorMessage message containing that password (or the staff number read from a staff badge). Upon receiving this message, the MIS/MES should authenticate the operator by checking in its centralized database of valid passwords, and matching a unique operator ID to the operator.

If authenticated, the MIS/MES should send an OperatorInfoMessage message to the iChen® System 4. This message should contain information regarding the authorization of that particular operator:

Upon receiving this reply message, the iChen® System 4 instructs the machine to recognize the appropriate access level of the operator, in addition to logging the operator’s ID for records.

If the password provided to the MIS/MES cannot be authenticated (i.e. if the password does not match any in its database), the MIS/MES should simply ignore this request or reply with an OperatorInfoMessage containing an operator ID of zero and an access level of zero.

When a staff member resigns and is transferred to another position, his/her password can simply be disabled from within the MIS/MES, and the staff can no longer gain access to any machine.

Integrated Job Scheduling

A machine can participate in the capacity planning of an MIS/MES, the MIS/MES is joined to the iChen® Server with a password that has the JobCards authority (see here for details).

The MIS/MES allocates and schedules units of work to individual machines via the concept of Job Cards.

A Job Card is single unit of work to be performed by one single machine. It can represent a single production order, or part of a production order that is allocated among certain number of machines during a particular time. The MIS/MES system is responsible for tracking, allocating and scheduling machines to satisfy

Typically a job card is identified by a unique textual ID value (which typically contains the unique order number that is it part of). Examples of job card ID’s:

ORDER12345-5-003 (The third machine for the first line item of order #12345)

C987-X2016(03)-42-005/008 (The fifth machine out of eight allocated to batch 42 of order X2016(03) of customer #987)

JKB-135/63 (63rd item for project code JKB-135)

A job card also typically contains at least the following pieces of information:

When connected to the iChen® System 4, a number of additional screens are enabled on a machine. The machine requests a valid list of job cards from the MIS/MES by sending the RequestJobCardsListMessage message with the machine’s serial number.

Upon receiving the RequestJobCardsListMessage message, the MIS/MES should search through its internal scheduling system and present the machine with all the valid job cards for that particular machine at that particular time of request.

Typically, only one job card is allocated to an individual machine at any time, so in most cases the list will contain only one job card item. In rare cases, when new ad-hoc jobs are inserted into the normal production schedule (i.e. barge-in), the list may contain more than one job card for the operator to choose from; however, in the interest of reducing operator errors, such practice should be avoided.

Depending on the authority of the operator, the machine typically should refuse to start production unless a valid job card is loaded. This can greatly reduce operator errors.

The MIS/MES provides the list of valid job cards to the iChen® System 4 via a JobCardsListMessage message. See also here for the format of each job card.

Each job card contains the unique ID of a mold to use. The machine then loads the set of parameter settings for the specified mold. Depending on the authority of the operator, he/she may not have authority to alter these settings, or may have only limited authority to alter certain settings but not others. This can greatly reduce operator errors during setup.

Each job card also contains the total quantity to be produced. Each piece of product counts as one, and so for multi-cavity molds, the total number of production cycles to be performed is the total quantity divided by the number of cavities.

The machine counts the quantity of “good” products produced, and when the requested quantity is fulfilled, the machine stops production and transit to an idle state. Depending on the authority of the operator, the machine may refuse to continue production beyond the requested quantity. This can greatly reduce the amount of over-production and wastage due to operator oversight.

In order to facilitate the above-mentioned quantity control, the MIS/MES should provide the current quantity already produced for each job card in addition to the total requested quantity. The machine, upon loading the job card, resets its internal “good” parts count to this quantity and starts incrementing from that.

The MIS/MES is also responsible for up-keeping the current quantity produced for each job card based on counting the cycle data messages sent by the machine (see here for details). In order to receive cycle data messages, the MIS/MES must be joined to the iChen® Server with a password that has the CycleData authority (see here for details). The machine is not supposed to track job card quantity numbers on a permanent basis; it is the responsibility of the MIS/MES to do so.

Integrated Mold Management

The iChen® System 4 stores mold settings data locally and automatically serves the correct data set upon request by a machine’s controller, transcoding the data sets wherever necessary to the appropriate versions acceptable by the requesting controller.

The iChen® System 4 also backs up the mold data sets to secure, protected and fault-tolerant cloud storage to ensure that no critical data is ever lost. All these are performed automatically and behind-the-scene. Normally, the MIS/MES does not need to care about this.

In certain circumstances, however, the MIS/MES would like to maintain such mold data sets centrally. There are a few ways to accomplish this:

(1) Request Live Mold Data

The MIS/MES sends a RequestMoldDataMessage to the iChen® System 4 for a particular machine (based on that machine’s unique serial number), which will respond with a MoldDataMessage containing the current settings data of the specified machine in the form of an binary array. The MIS/MES can then store this data centrally.

(2) Use the Mold Data REST API

The iChen® System 4 exposes a Mold Data REST API that allows the MIS/MES to inspect, add and delete stored mold data sets. It is up to the MIS/MES to synchronize its mold data sets database with that in the iChen® System 4.

(3) Mold Data Integration Module (Optional)

An optional Mold Data Integration Module can be installed in the iChen® System 4 to completely by-pass its internal mold data storage, always going to the MIS/MES instead.

The Mold Data Integration Module is a separately-charged product.